Cogan Syndrome

Autoimmune MONDO:0015453 Pathograph 25 Autoimmune Disease Vasculitis Inner Ear Diseases

Rare autoimmune vasculitis characterized by ocular inflammation and audiovestibular involvement, often with systemic vasculitis.

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8
Pathophys.
2
Histopath.
17
Phenotypes
1
Hypotheses
25
Pathograph
4
Medical Actions
2
Subtypes
3
Differentials
1
Trials
5
References
1
Deep Research
🏷

Classifications

Harrison's Chapter
IMMUNE_RHEUMATOLOGIC
◆

Subtypes

2
Typical Cogan syndrome
Non-syphilitic interstitial keratitis with audiovestibular symptoms.
Show evidence (2 references)
PMID:24979832 SUPPORT Human Clinical
""typical" form with non-syphilitic interstitial keratitis and audiovestibular symptoms"
Typical Cogan syndrome is defined by interstitial keratitis with audiovestibular symptoms.
PMID:28583785 SUPPORT Human Clinical
"classically defined as the combination of nonsyphilitic interstitial keratitis and audiovestibular symptoms resembling Meniere's disease, both of them developed in an interval of less than two years."
Case report reiterates the classic definition of typical Cogan syndrome.
Atypical Cogan syndrome
Ocular involvement affecting structures other than the cornea.
Show evidence (1 reference)
PMID:24979832 SUPPORT Human Clinical
"an "atypical" form with ocular involvement affecting structures other than the cornea"
Atypical Cogan syndrome is defined by non-corneal ocular involvement.
◈

Mechanistic Hypotheses

1
Post-infectious molecular mimicry model
molecular_mimicry_postinfectious EMERGING
The leading model holds that an antecedent infection triggers an autoimmune response via molecular mimicry: an immunodominant peptide recognized by patient IgG shares sequence similarity with the reovirus III major core protein and the SSA/Ro autoantigen, generating autoantibodies that cross-react with inner-ear and endothelial self-antigens (CD148/DEP-1, connexin 26) and drive tissue injury.
Status EMERGING because the pathogenesis is described in the literature as unknown; the mimicry epitope and animal passive-transfer data are the strongest mechanistic support but a definitive infectious trigger is unproven. The trigger-level downstream edges on the "Molecular mimicry and autoantibody generation" pathophysiology node opt into this hypothesis group.
Pathograph links
Molecular mimicry and autoantibody generation -> Autoantibodies target corneal antigens DIRECT Cross-reactive autoantibodies recognize corneal self-antigens.
Molecular mimicry and autoantibody generation -> Autoantibodies target inner ear antigens DIRECT Cross-reactive autoantibodies recognize inner-ear self-antigens.
Molecular mimicry and autoantibody generation -> Autoantibodies bind CD148 on inner ear sensory epithelium and endothelial cells DIRECT Mimicry with DEP-1/CD148 generates antibodies binding inner-ear sensory epithelium and endothelium.
Molecular mimicry and autoantibody generation -> Autoantibodies bind connexin 26 DIRECT The same antibodies cross-react with connexin 26 in the inner ear.
Molecular mimicry and autoantibody generation -> Autoantibodies target endothelial antigens DIRECT Cross-reactive autoantibodies recognize endothelial self-antigens.
Show evidence (2 references)
PMID:12354474 SUPPORT Human Clinical
"We identified an immunodominant peptide that shows similarity with autoantigens such as SSA/Ro and with the reovirus III major core protein"
Peptide-library identification of a mimicry epitope shared with a reovirus protein and SSA/Ro is the molecular basis for the post-infectious mimicry model.
PMID:22846458 SUPPORT Human Clinical
"Infection, but primarily autoimmunity, may play contributing roles in the pathogenesis of this disease."
Review supports infection as a contributing trigger while emphasizing that pathogenesis remains incompletely defined, justifying EMERGING status.
⚙

Pathophysiology

8
Molecular mimicry and autoantibody generation
The proposed initiating mechanism is post-infectious molecular mimicry. An immunodominant peptide recognized by IgG from Cogan syndrome patients shares sequence similarity with the reovirus III major core protein and the SSA/Ro autoantigen, breaking immune tolerance and generating autoantibodies that cross-react with inner-ear and endothelial self-antigens (including CD148/DEP-1 and connexin 26). Infection may contribute, but autoimmunity is regarded as the primary driver; the pathogenesis remains incompletely defined.
Post-infectious molecular mimicry model
immunoglobulin production GO:0002377 ↕ DYSREGULATED adaptive immune response GO:0002250 ↕ DYSREGULATED
Downstream
Autoantibodies target corneal antigens Cross-reactive autoantibodies recognize corneal self-antigens. Post-infectious molecular mimicry model
Autoantibodies target inner ear antigens Cross-reactive autoantibodies recognize inner-ear self-antigens. Post-infectious molecular mimicry model
Autoantibodies bind CD148 on inner ear sensory epithelium and endothelial cells Mimicry with DEP-1/CD148 generates antibodies binding inner-ear sensory epithelium and endothelium. Post-infectious molecular mimicry model
Autoantibodies bind connexin 26 The same antibodies cross-react with connexin 26 in the inner ear. Post-infectious molecular mimicry model
Autoantibodies target endothelial antigens Cross-reactive autoantibodies recognize endothelial self-antigens. Post-infectious molecular mimicry model
Show evidence (2 references)
PMID:12354474 SUPPORT Human Clinical
"We identified an immunodominant peptide that shows similarity with autoantigens such as SSA/Ro and with the reovirus III major core protein"
The immunodominant Cogan peptide's similarity to a reovirus protein and the SSA/Ro autoantigen is the molecular-mimicry basis for autoantibody generation.
PMID:22846458 SUPPORT Human Clinical
"Infection, but primarily autoimmunity, may play contributing roles in the pathogenesis of this disease."
Review frames infection as a contributing trigger with autoimmunity as the primary pathogenic mechanism.
Autoantibodies target corneal antigens
Autoantibodies recognize corneal antigens.
corneal epithelial cell CL:0000575
Downstream
Keratitis Antibody-mediated corneal inflammation produces interstitial keratitis.
Show evidence (1 reference)
PMID:22846458 SUPPORT Human Clinical
"auto-antibodies against corneal, inner ear and endothelial antigens"
Review includes corneal antigens among autoantibody targets.
Autoantibodies target inner ear antigens
Autoantibodies recognize inner ear antigens.
sensory epithelial cell CL:0000098
Downstream
Immune-mediated inner ear injury Antibody binding to inner-ear antigens initiates immune-mediated cochleovestibular injury.
Show evidence (2 references)
PMID:22846458 SUPPORT Human Clinical
"auto-antibodies against corneal, inner ear and endothelial antigens"
Review includes inner ear antigens among autoantibody targets.
PMID:12354474 SUPPORT Human Clinical
"Autoantibodies to inner ear and endothelial antigens in Cogan's syndrome."
Study reports autoantibodies directed at inner ear antigens.
Autoantibodies bind CD148 on inner ear sensory epithelium and endothelial cells
Autoantibodies recognize CD148/DEP-1 expressed on inner ear sensory epithelium and endothelial cells.
sensory epithelial cell CL:0000098 endothelial cell CL:0000115
Downstream
Immune-mediated inner ear injury Antibody binding to CD148/DEP-1 on inner-ear sensory epithelium contributes to cochleovestibular injury.
Systemic vasculitic inflammation Antibody binding to CD148/DEP-1 on endothelial cells contributes to endothelial activation and systemic vasculitis.
Show evidence (1 reference)
PMID:12354474 SUPPORT Human Clinical
"The peptide sequence shows similarity also with the cell-density enhanced protein tyrosine phosphatase-1 (DEP-1/CD148), which is expressed on the sensory epithelia of the inner ear and on endothelial cells."
Autoantibody target CD148 is expressed on inner ear sensory epithelium and endothelial cells.
Autoantibodies bind connexin 26
Autoantibodies recognize connexin 26 in the inner ear.
sensory epithelial cell CL:0000098
Downstream
Immune-mediated inner ear injury Antibody cross-reactivity with connexin 26 in the inner ear contributes to cochleovestibular injury.
Show evidence (1 reference)
PMID:12354474 SUPPORT Human Clinical
"The same antibodies bound connexin 26"
Autoantibodies bind connexin 26, linking autoimmune response to inner ear targets.
Autoantibodies target endothelial antigens
Autoantibodies recognize endothelial antigens.
endothelial cell CL:0000115
Downstream
Systemic vasculitic inflammation Antibody binding to endothelial antigens promotes endothelial injury and systemic vasculitis.
Show evidence (2 references)
PMID:22846458 SUPPORT Human Clinical
"auto-antibodies against corneal, inner ear and endothelial antigens"
Review includes endothelial antigens among autoantibody targets.
PMID:12354474 SUPPORT Human Clinical
"Autoantibodies to inner ear and endothelial antigens in Cogan's syndrome."
Study reports autoantibodies directed at endothelial antigens.
Immune-mediated inner ear injury
Convergent immune-mediated injury of the cochlear and vestibular sensory epithelia. Patient-derived autoantibodies bind human cochlea, and temporal-bone histopathology demonstrates endolymphatic hydrops and degenerative changes across multiple inner-ear structures, producing progressive audiovestibular dysfunction.
sensory epithelial cell CL:0000098 auditory hair cell CL:0000202
inflammatory response GO:0006954 ↑ INCREASED
Downstream
Sensorineural hearing impairment Cochlear sensory epithelial injury produces sensorineural hearing loss.
Vertigo Vestibular sensory injury produces rotational vertigo.
Tinnitus Cochlear injury produces tinnitus.
Absent vestibular function Progressive vestibular sensory loss produces bilateral vestibular hypofunction.
Show evidence (2 references)
PMID:12354474 SUPPORT Human Clinical
"bound human cochlea"
Affinity-purified patient antibodies bind human cochlea, supporting direct antibody-mediated inner-ear targeting.
PMID:38973571 SUPPORT Human Clinical
"degenerative changes in various parts of the inner ear"
Temporal-bone histopathology confirms degenerative inner-ear injury underlying audiovestibular phenotypes.
Systemic vasculitic inflammation
Downstream systemic vasculitic inflammation involving multiple organs.
immune system process GO:0002376 ↕ DYSREGULATED inflammatory response GO:0006954 ↕ DYSREGULATED
Downstream
Vasculitis Systemic immune-mediated vascular inflammation manifests as clinically apparent vasculitis.
Large vessel vasculitis Vascular inflammation can involve the aorta and other large vessels.
Medium vessel vasculitis Vascular inflammation can involve medium-caliber arteries.
Arteritis Arterial wall inflammation, including coronary arteritis, can occur.
Aortitis Aortic-wall inflammation is a large-vessel manifestation of systemic vasculitis.
Retinal vasculitis Vasculitic involvement of retinal vessels in atypical ocular disease.
Episcleritis Inflammation of episcleral vasculature as an ocular manifestation.
Uveitis Ocular immune-mediated inflammation manifesting as uveitis in atypical disease.
Panuveitis Diffuse intraocular immune-mediated inflammation manifesting as panuveitis.
Show evidence (2 references)
PMID:22846458 SUPPORT Human Clinical
"Cogan's syndrome is a rare autoimmune vasculitis"
Review describes Cogan syndrome as an autoimmune vasculitis.
PMID:24979832 SUPPORT Human Clinical
"Cogan's syndrome (CS) is a rare autoimmune vasculitis characterized by ocular inflammation and sensorineural hearing loss."
Review links autoimmune vasculitis to ocular and audiovestibular manifestations.
✶

Histopathology

2
Endolymphatic hydrops
Histology of the temporal bone shows endolymphatic hydrops.
Show evidence (1 reference)
PMID:38973571 SUPPORT Human Clinical
"findings revealed endolymphatic hydrops"
Temporal bone histopathology demonstrates endolymphatic hydrops in atypical Cogan syndrome.
Inner ear degenerative changes
Degenerative changes are seen in multiple inner ear structures.
Show evidence (1 reference)
PMID:38973571 SUPPORT Human Clinical
"degenerative changes in various parts of the inner ear"
Temporal bone histology shows degenerative changes across inner ear structures.
⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for Cogan Syndrome Interactive directed graph showing how pathophysiology mechanisms, phenotypes, genetic factors and variants, experimental models, environmental triggers, and treatments relate through causal and linked edges.
●

Phenotypes

17
Cardiovascular 8
Retinal vasculitis OCCASIONAL Retinal vasculitis HP:0025188
Show evidence (1 reference)
PMID:39280458 SUPPORT Human Clinical
"Uveitis with retinal vasculitis was observed in both eyes"
Case report documents bilateral retinal vasculitis in atypical Cogan syndrome.
Aortic regurgitation VERY_RARE Aortic regurgitation HP:0001659
Show evidence (1 reference)
PMID:40843044 SUPPORT Human Clinical
"presented with newly diagnosed, severe aortic regurgitation (AR)"
Case report documents severe aortic regurgitation in Cogan syndrome.
Coronary artery stenosis VERY_RARE Coronary artery stenosis HP:0005145
Sequelae: Acute coronary syndrome
Show evidence (1 reference)
PMID:39328241 SUPPORT Human Clinical
"recurrent coronary artery stenosis"
Case report describes recurrent coronary artery stenosis in Cogan syndrome.
Vasculitis FREQUENT Vasculitis HP:0002633
Show evidence (3 references)
PMID:22846458 SUPPORT Human Clinical
"Approximately 70% of patients have systemic disease, of which vasculitis is considered the pathological mechanism."
Review reports frequent systemic vasculitis.
PMID:12354474 SUPPORT Human Clinical
"characterised by sensorineural hearing loss, episcleritis, and vasculitis."
Study includes vasculitis among defining features.
PMID:27330475 SUPPORT Human Clinical
"Almost half of patients develop systemic manifestations."
Case report notes systemic manifestations, consistent with vasculitic disease.
Large vessel vasculitis OCCASIONAL Large vessel vasculitis HP:0005310
Show evidence (3 references)
PMID:28583785 SUPPORT Human Clinical
"late-onset Cogan's syndrome associated with a large-vessel vasculitis."
Case report documents large-vessel vasculitis in Cogan syndrome.
PMID:29489984 SUPPORT Human Clinical
"The inflammation of aortic wall, named aortitis, is a rare condition"
Aortitis is a large-vessel inflammatory manifestation reported in Cogan syndrome.
PMID:27330475 SUPPORT Human Clinical
"severe medium and large vessel vasculitis"
Case report describes severe large-vessel vasculitis in Cogan syndrome.
Medium vessel vasculitis OCCASIONAL Medium vessel vasculitis HP:6000658
Show evidence (1 reference)
PMID:27330475 SUPPORT Human Clinical
"severe medium and large vessel vasculitis"
Case report documents medium-vessel vasculitis as a systemic manifestation.
Arteritis OCCASIONAL Arteritis HP:0012089
Sequelae: Coronary artery stenosis
Show evidence (3 references)
PMID:39999281 SUPPORT Human Clinical
"multiple arteritis involving the coronary artery"
Case report describes multiple arteritis with coronary involvement in Cogan syndrome.
PMID:40054904 SUPPORT Human Clinical
"Cogan syndrome, a rare multisystemic autoimmune vasculitis, can result in coronaritis"
Case report notes coronaritis in Cogan syndrome.
PMID:39328241 SUPPORT Human Clinical
"Cogan's syndrome (CS) is recognized as a form of variable vasculitis."
Case report reiterates vasculitis classification in Cogan syndrome.
Acute coronary syndrome VERY_RARE Acute coronary syndrome HP:0033678
Show evidence (2 references)
PMID:40054904 SUPPORT Human Clinical
"can result in coronaritis and precipitate acute coronary syndrome."
Case report describes acute coronary syndrome in Cogan syndrome with coronaritis.
PMID:39007044 SUPPORT Human Clinical
"anterior ST-elevation myocardial infarction"
Case report documents STEMI as an acute coronary syndrome manifestation in Cogan syndrome.
Ear 4
Sensorineural hearing impairment FREQUENT Sensorineural hearing impairment HP:0000407
Show evidence (5 references)
PMID:24979832 SUPPORT Human Clinical
"Cogan's syndrome (CS) is a rare autoimmune vasculitis characterized by ocular inflammation and sensorineural hearing loss."
Review notes sensorineural hearing loss as a defining feature.
PMID:41473897 SUPPORT Human Clinical
"Bilateral, asymmetric hearing impairment manifested as sudden sensorineural hearing loss"
Case series reports sudden sensorineural hearing loss in Cogan syndrome.
PMID:40866103 SUPPORT Human Clinical
"remote history of chronic iritis and bilateral sensorineural hearing loss"
Case report documents bilateral sensorineural hearing loss in atypical Cogan syndrome.
+ 2 more references
Vertigo FREQUENT Vertigo HP:0002321
Show evidence (3 references)
PMID:39455380 SUPPORT Human Clinical
"It is characterised by the sudden onset of continuous rotational vertigo associated with tinnitus"
French protocol describes sudden continuous rotational vertigo in cochleo-vestibular involvement.
PMID:39543746 SUPPORT Human Clinical
"isolated and fluctuating audiovestibular Ménière-like symptoms"
Case report notes Menière-like audiovestibular symptoms consistent with vertigo.
PMID:39280458 SUPPORT Human Clinical
"Inner ear symptoms include sensorineural hearing loss, rotatory vertigo, and tinnitus"
Case report summary reiterates rotatory vertigo as an inner ear symptom.
Tinnitus FREQUENT Tinnitus HP:0000360
Show evidence (3 references)
PMID:39455380 SUPPORT Human Clinical
"It is characterised by the sudden onset of continuous rotational vertigo associated with tinnitus"
French protocol notes tinnitus as part of cochleo-vestibular involvement.
PMID:39543746 SUPPORT Human Clinical
"isolated and fluctuating audiovestibular Ménière-like symptoms"
Case report describes Menière-like symptoms consistent with tinnitus.
PMID:39280458 SUPPORT Human Clinical
"Inner ear symptoms include sensorineural hearing loss, rotatory vertigo, and tinnitus"
Case report summary includes tinnitus among inner ear symptoms.
Absent vestibular function OCCASIONAL Absent vestibular function HP:0008555
Show evidence (3 references)
PMID:41473897 SUPPORT Human Clinical
"all patients experienced loss of bilateral vestibular function"
Case series reports loss of bilateral vestibular function in Cogan syndrome.
PMID:39268327 SUPPORT Human Clinical
"bilateral vestibular dysfunction"
Pediatric case report documents bilateral vestibular dysfunction.
PMID:36502531 SUPPORT Human Clinical
"Cogan's syndrome (CS) is a rare inflammatory disease characterized by interstitial keratitis or uveitis, vestibular impairment, and progressive hearing loss, commonly bilateral."
Pediatric review notes vestibular impairment as a key manifestation.
Eye 4
Keratitis FREQUENT Keratitis HP:0000491
Show evidence (3 references)
PMID:24979832 SUPPORT Human Clinical
""typical" form with non-syphilitic interstitial keratitis and audiovestibular symptoms"
Typical Cogan syndrome includes interstitial keratitis.
PMID:39328241 SUPPORT Human Clinical
"history of non-syphilis keratitis"
Case report documents keratitis in Cogan syndrome.
PMID:36502531 SUPPORT Human Clinical
"Cogan's syndrome (CS) is a rare inflammatory disease characterized by interstitial keratitis or uveitis, vestibular impairment, and progressive hearing loss, commonly bilateral."
Pediatric review notes interstitial keratitis as a defining manifestation.
Uveitis OCCASIONAL Uveitis HP:0000554
Show evidence (1 reference)
PMID:36502531 SUPPORT Human Clinical
"Cogan's syndrome (CS) is a rare inflammatory disease characterized by interstitial keratitis or uveitis, vestibular impairment, and progressive hearing loss, commonly bilateral."
Pediatric review highlights uveitis as a core ocular manifestation.
Episcleritis OCCASIONAL Episcleritis HP:0100534
Show evidence (1 reference)
PMID:12354474 SUPPORT Human Clinical
"characterised by sensorineural hearing loss, episcleritis, and vasculitis."
Study lists episcleritis as a characteristic clinical feature.
Panuveitis OCCASIONAL Panuveitis HP:0012121
Show evidence (1 reference)
PMID:39268327 SUPPORT Human Clinical
"The patient had panuveitis"
Pediatric case report documents panuveitis in Cogan syndrome.
Other 1
Aortitis OCCASIONAL Aortitis HP:6001461
Sequelae: Aortic regurgitation
Show evidence (2 references)
PMID:29489984 SUPPORT Human Clinical
"The inflammation of aortic wall, named aortitis, is a rare condition that can be caused by a number of pathologies, mainly inflammatory or infectious in nature. In this context, the occurrence of combined audiovestibular and/or ocular manifestations eventually led to the diagnosis of Cogan's syndrome"
Case report ties aortitis to Cogan syndrome diagnosis.
PMID:36502531 SUPPORT Human Clinical
"Also, aortic involvement was present in 19.5% of patients in the literature."
Pediatric systematic review reports aortic involvement frequency.
💊

Medical Actions

4
Corticosteroid therapy
Action: systemic corticosteroid therapy Ontology label: Systemic Corticosteroid Therapy NCIT:C122080
Agent: prednisone CHEBI:8382
Corticosteroids are first-line therapy for Cogan syndrome.
Show evidence (2 references)
PMID:22846458 SUPPORT Human Clinical
"Corticosteroids are the first line of treatment"
Review identifies corticosteroids as first-line therapy.
PMID:36502531 SUPPORT Human Clinical
"Although glucocorticoids are fundamental treatment options"
Pediatric review highlights glucocorticoids as fundamental therapy.
Immunosuppressive therapy
Action: immunosuppressive therapy Ontology label: immune suppressant agent therapy MAXO:0000297
Agent: methotrexate CHEBI:44185 cyclophosphamide CHEBI:4027 cyclosporin A CHEBI:4031
Immunosuppressive agents are used for refractory or systemic disease.
Show evidence (3 references)
PMID:41473897 SUPPORT Human Clinical
"immunosuppressive therapy (methotrexate, cyclophosphamide, cyclosporin A)"
Case series reports use of multiple immunosuppressive agents.
PMID:40866103 SUPPORT Human Clinical
"she was started on systemic corticosteroids with rapid improvement in visual acuity and resolution of symptoms."
Case report illustrates systemic therapy response in atypical Cogan syndrome.
PMID:36502531 SUPPORT Human Clinical
"treated with corticosteroids and methotrexate."
Pediatric cases used methotrexate as an immunosuppressive agent.
TNF-alpha inhibitor therapy
Action: Pharmacotherapy NCIT:C15986
TNF-alpha blockers represent a novel immunosuppressive option.
Show evidence (3 references)
PMID:22846458 SUPPORT Human Clinical
"Tumour necrosis factor (TNF)-alpha blockers are a category of immunosuppressive agents representing a recent novel therapeutic option in Cogan's syndrome."
Review notes TNF-alpha blockers as a therapeutic option.
PMID:39455380 SUPPORT Human Clinical
"Combination with anti-TNF therapy should be promptly discussed."
Protocol recommends prompt consideration of anti-TNF therapy.
PMID:41473897 SUPPORT Human Clinical
"biological treatment (infliximab, adalimumab)"
Case series reports biologic anti-TNF agents used in Cogan syndrome.
Cochlear device implantation
Action: cochlear device implantation MAXO:0009025
Cochlear implantation is used for hearing rehabilitation in severe hearing loss.
Show evidence (2 references)
PMID:41473897 SUPPORT Human Clinical
"four patients were treated with cochlear implantation and achieved long-term stable speech perception."
Case series reports cochlear implantation with stable long-term outcomes.
PMID:36502531 SUPPORT Human Clinical
"One patient had a cochlear implant"
Pediatric case report includes cochlear implantation.
🔀

Differential Diagnoses

3

Conditions with similar clinical presentations that must be differentiated from Cogan Syndrome:

Meniere disease MONDO:0007972
Overlapping Features Audiovestibular symptoms can mimic Meniere disease.
Show evidence (1 reference)
PMID:22846458 SUPPORT Human Clinical
"audiovestibular symptoms similar to those of Meniere's syndrome."
Review notes audiovestibular symptoms resembling Meniere disease, supporting it as a differential.
Takayasu arteritis MONDO:0017991
Overlapping Features Large-vessel vasculitis can overlap with systemic Cogan syndrome.
Show evidence (1 reference)
PMID:39455380 SUPPORT Human Clinical
"Association with other autoimmune diseases, particularly other forms of vasculitis such as polyarteritis nodosa or Takayasu's arteritis, is possible."
Protocol notes association with Takayasu arteritis.
Polyarteritis nodosa Not Yet Curated MONDO:0019170
Overlapping Features Medium-vessel vasculitis can be associated with Cogan syndrome.
Show evidence (1 reference)
PMID:39455380 SUPPORT Human Clinical
"Association with other autoimmune diseases, particularly other forms of vasculitis such as polyarteritis nodosa or Takayasu's arteritis, is possible."
Protocol notes association with polyarteritis nodosa.
🔬

Clinical Trials

1
NCT05168475 PHASE_II TERMINATED
BIOVAS — a randomised, double-blind, placebo-controlled, modified-crossover trial of biologic therapy (including rituximab, tocilizumab, and infliximab) for refractory primary non-ANCA-associated vasculitis in adults and children. Cogan syndrome is one of the enrolled non-ANCA-associated vasculitides.
Target Phenotypes: Vasculitis HP:0002633
Show evidence (1 reference)
clinicaltrials:NCT05168475 SUPPORT Human Clinical
"The trial will include patients with Non-ANCA-associated vasculitis (NAAV)"
BIOVAS enrolls non-ANCA-associated vasculitides, with Cogan Syndrome listed among the trial's conditions, evaluating biologic therapy for refractory disease.
{ }

Source YAML

click to show 
name: Cogan Syndrome
creation_date: '2026-02-04T15:55:07Z'
updated_date: '2026-05-08T20:47:43Z'
category: Autoimmune
synonyms:
- Cogan syndrome
- Cogan's syndrome
description: >-
  Rare autoimmune vasculitis characterized by ocular inflammation and
  audiovestibular involvement, often with systemic vasculitis.
disease_term:
  preferred_term: Cogan syndrome
  term:
    id: MONDO:0015453
    label: Cogan syndrome
parents:
- Autoimmune Disease
- Vasculitis
- Inner Ear Diseases
classifications:
  harrisons_chapter:
  - classification_value: IMMUNE_RHEUMATOLOGIC
prevalence:
- population: Pediatric cases in literature
  notes: Systematic review identified 34 articles describing 44 pediatric patients.
  evidence:
  - reference: PMID:36502531
    reference_title: "Report of 2 pediatric cases with atypical Cogan's syndrome and a systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In the literature, 34 articles describing 44 pediatric patients with CS were identified."
    explanation: Systematic review quantifies reported pediatric cases in the literature.
has_subtypes:
- name: Typical Cogan syndrome
  description: Non-syphilitic interstitial keratitis with audiovestibular symptoms.
  evidence:
  - reference: PMID:24979832
    reference_title: "Cogan's syndrome: anti-Hsp70 antibodies are a serological marker in the typical form."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: '"typical" form with non-syphilitic interstitial keratitis and audiovestibular symptoms'
    explanation: Typical Cogan syndrome is defined by interstitial keratitis with audiovestibular symptoms.
  - reference: PMID:28583785
    reference_title: "Late-onset Cogan's syndrome associated with large-vessel vasculitis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "classically defined as the combination of nonsyphilitic interstitial keratitis and audiovestibular symptoms resembling Meniere's disease, both of them developed in an interval of less than two years."
    explanation: Case report reiterates the classic definition of typical Cogan syndrome.
- name: Atypical Cogan syndrome
  description: Ocular involvement affecting structures other than the cornea.
  evidence:
  - reference: PMID:24979832
    reference_title: "Cogan's syndrome: anti-Hsp70 antibodies are a serological marker in the typical form."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "an \"atypical\" form with ocular involvement affecting structures other than the cornea"
    explanation: Atypical Cogan syndrome is defined by non-corneal ocular involvement.
pathophysiology:
- name: Molecular mimicry and autoantibody generation
  description: >-
    The proposed initiating mechanism is post-infectious molecular mimicry. An
    immunodominant peptide recognized by IgG from Cogan syndrome patients shares
    sequence similarity with the reovirus III major core protein and the SSA/Ro
    autoantigen, breaking immune tolerance and generating autoantibodies that
    cross-react with inner-ear and endothelial self-antigens (including CD148/DEP-1
    and connexin 26). Infection may contribute, but autoimmunity is regarded as the
    primary driver; the pathogenesis remains incompletely defined.
  biological_processes:
  - preferred_term: immunoglobulin production
    term:
      id: GO:0002377
      label: immunoglobulin production
    modifier: DYSREGULATED
  - preferred_term: adaptive immune response
    term:
      id: GO:0002250
      label: adaptive immune response
    modifier: DYSREGULATED
  evidence:
  - reference: PMID:12354474
    reference_title: "Autoantibodies to inner ear and endothelial antigens in Cogan's syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We identified an immunodominant peptide that shows similarity with autoantigens such as SSA/Ro and with the reovirus III major core protein"
    explanation: The immunodominant Cogan peptide's similarity to a reovirus protein and the SSA/Ro autoantigen is the molecular-mimicry basis for autoantibody generation.
  - reference: PMID:22846458
    reference_title: "Cogan's syndrome: an autoimmune inner ear disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Infection, but primarily autoimmunity, may play contributing roles in the pathogenesis of this disease."
    explanation: Review frames infection as a contributing trigger with autoimmunity as the primary pathogenic mechanism.
  downstream:
  - target: Autoantibodies target corneal antigens
    description: Cross-reactive autoantibodies recognize corneal self-antigens.
    causal_link_type: DIRECT
    hypothesis_groups:
    - molecular_mimicry_postinfectious
  - target: Autoantibodies target inner ear antigens
    description: Cross-reactive autoantibodies recognize inner-ear self-antigens.
    causal_link_type: DIRECT
    hypothesis_groups:
    - molecular_mimicry_postinfectious
  - target: Autoantibodies bind CD148 on inner ear sensory epithelium and endothelial cells
    description: Mimicry with DEP-1/CD148 generates antibodies binding inner-ear sensory epithelium and endothelium.
    causal_link_type: DIRECT
    hypothesis_groups:
    - molecular_mimicry_postinfectious
  - target: Autoantibodies bind connexin 26
    description: The same antibodies cross-react with connexin 26 in the inner ear.
    causal_link_type: DIRECT
    hypothesis_groups:
    - molecular_mimicry_postinfectious
  - target: Autoantibodies target endothelial antigens
    description: Cross-reactive autoantibodies recognize endothelial self-antigens.
    causal_link_type: DIRECT
    hypothesis_groups:
    - molecular_mimicry_postinfectious
- name: Autoantibodies target corneal antigens
  description: Autoantibodies recognize corneal antigens.
  cell_types:
  - preferred_term: corneal epithelial cell
    term:
      id: CL:0000575
      label: corneal epithelial cell
  evidence:
  - reference: PMID:22846458
    reference_title: "Cogan's syndrome: an autoimmune inner ear disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "auto-antibodies against corneal, inner ear and endothelial antigens"
    explanation: Review includes corneal antigens among autoantibody targets.
  downstream:
  - target: Keratitis
    description: Antibody-mediated corneal inflammation produces interstitial keratitis.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - corneal antigen-antibody binding
    - local inflammatory infiltration
- name: Autoantibodies target inner ear antigens
  description: Autoantibodies recognize inner ear antigens.
  cell_types:
  - preferred_term: sensory epithelial cell
    term:
      id: CL:0000098
      label: sensory epithelial cell
  evidence:
  - reference: PMID:22846458
    reference_title: "Cogan's syndrome: an autoimmune inner ear disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "auto-antibodies against corneal, inner ear and endothelial antigens"
    explanation: Review includes inner ear antigens among autoantibody targets.
  - reference: PMID:12354474
    reference_title: "Autoantibodies to inner ear and endothelial antigens in Cogan's syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Autoantibodies to inner ear and endothelial antigens in Cogan's syndrome."
    explanation: Study reports autoantibodies directed at inner ear antigens.
  downstream:
  - target: Immune-mediated inner ear injury
    description: Antibody binding to inner-ear antigens initiates immune-mediated cochleovestibular injury.
    causal_link_type: DIRECT
- name: Autoantibodies bind CD148 on inner ear sensory epithelium and endothelial cells
  description: Autoantibodies recognize CD148/DEP-1 expressed on inner ear sensory epithelium and endothelial cells.
  cell_types:
  - preferred_term: sensory epithelial cell
    term:
      id: CL:0000098
      label: sensory epithelial cell
  - preferred_term: endothelial cell
    term:
      id: CL:0000115
      label: endothelial cell
  evidence:
  - reference: PMID:12354474
    reference_title: "Autoantibodies to inner ear and endothelial antigens in Cogan's syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The peptide sequence shows similarity also with the cell-density enhanced protein tyrosine phosphatase-1 (DEP-1/CD148), which is expressed on the sensory epithelia of the inner ear and on endothelial cells."
    explanation: Autoantibody target CD148 is expressed on inner ear sensory epithelium and endothelial cells.
  notes: >-
    Anti-CD148/DEP-1 autoantibodies were characterised in a research setting:
    purified patient IgG inhibited proliferation of DEP-1/CD148-expressing cells
    and passive transfer reproduced features of Cogan syndrome in mice, establishing
    pathogenic potential. Despite promising research-stage diagnostic performance,
    anti-CD148 antibody testing is not routinely available and is not part of the
    standard diagnostic workup; diagnosis of Cogan syndrome remains clinical and
    exclusionary. This biomarker is therefore represented here as pathophysiology
    rather than as a clinical diagnostic test.
  downstream:
  - target: Immune-mediated inner ear injury
    description: Antibody binding to CD148/DEP-1 on inner-ear sensory epithelium contributes to cochleovestibular injury.
    causal_link_type: DIRECT
  - target: Systemic vasculitic inflammation
    description: Antibody binding to CD148/DEP-1 on endothelial cells contributes to endothelial activation and systemic vasculitis.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - endothelial antibody binding
    - endothelial activation
- name: Autoantibodies bind connexin 26
  description: Autoantibodies recognize connexin 26 in the inner ear.
  cell_types:
  - preferred_term: sensory epithelial cell
    term:
      id: CL:0000098
      label: sensory epithelial cell
  evidence:
  - reference: PMID:12354474
    reference_title: "Autoantibodies to inner ear and endothelial antigens in Cogan's syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The same antibodies bound connexin 26"
    explanation: Autoantibodies bind connexin 26, linking autoimmune response to inner ear targets.
  downstream:
  - target: Immune-mediated inner ear injury
    description: Antibody cross-reactivity with connexin 26 in the inner ear contributes to cochleovestibular injury.
    causal_link_type: DIRECT
- name: Autoantibodies target endothelial antigens
  description: Autoantibodies recognize endothelial antigens.
  cell_types:
  - preferred_term: endothelial cell
    term:
      id: CL:0000115
      label: endothelial cell
  evidence:
  - reference: PMID:22846458
    reference_title: "Cogan's syndrome: an autoimmune inner ear disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "auto-antibodies against corneal, inner ear and endothelial antigens"
    explanation: Review includes endothelial antigens among autoantibody targets.
  - reference: PMID:12354474
    reference_title: "Autoantibodies to inner ear and endothelial antigens in Cogan's syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Autoantibodies to inner ear and endothelial antigens in Cogan's syndrome."
    explanation: Study reports autoantibodies directed at endothelial antigens.
  downstream:
  - target: Systemic vasculitic inflammation
    description: Antibody binding to endothelial antigens promotes endothelial injury and systemic vasculitis.
    causal_link_type: DIRECT
- name: Immune-mediated inner ear injury
  description: >-
    Convergent immune-mediated injury of the cochlear and vestibular sensory
    epithelia. Patient-derived autoantibodies bind human cochlea, and temporal-bone
    histopathology demonstrates endolymphatic hydrops and degenerative changes
    across multiple inner-ear structures, producing progressive audiovestibular
    dysfunction.
  cell_types:
  - preferred_term: sensory epithelial cell
    term:
      id: CL:0000098
      label: sensory epithelial cell
  - preferred_term: auditory hair cell
    term:
      id: CL:0000202
      label: auditory hair cell
  biological_processes:
  - preferred_term: inflammatory response
    term:
      id: GO:0006954
      label: inflammatory response
    modifier: INCREASED
  evidence:
  - reference: PMID:12354474
    reference_title: "Autoantibodies to inner ear and endothelial antigens in Cogan's syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "bound human cochlea"
    explanation: Affinity-purified patient antibodies bind human cochlea, supporting direct antibody-mediated inner-ear targeting.
  - reference: PMID:38973571
    reference_title: "Temporal Bone Histopathology of Atypical Cogan Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "degenerative changes in various parts of the inner ear"
    explanation: Temporal-bone histopathology confirms degenerative inner-ear injury underlying audiovestibular phenotypes.
  downstream:
  - target: Sensorineural hearing impairment
    description: Cochlear sensory epithelial injury produces sensorineural hearing loss.
    causal_link_type: DIRECT
  - target: Vertigo
    description: Vestibular sensory injury produces rotational vertigo.
    causal_link_type: DIRECT
  - target: Tinnitus
    description: Cochlear injury produces tinnitus.
    causal_link_type: DIRECT
  - target: Absent vestibular function
    description: Progressive vestibular sensory loss produces bilateral vestibular hypofunction.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - progressive vestibular hair cell loss
- name: Systemic vasculitic inflammation
  description: Downstream systemic vasculitic inflammation involving multiple organs.
  biological_processes:
  - preferred_term: immune system process
    term:
      id: GO:0002376
      label: immune system process
    modifier: DYSREGULATED
  - preferred_term: inflammatory response
    term:
      id: GO:0006954
      label: inflammatory response
    modifier: DYSREGULATED
  evidence:
  - reference: PMID:22846458
    reference_title: "Cogan's syndrome: an autoimmune inner ear disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Cogan's syndrome is a rare autoimmune vasculitis"
    explanation: Review describes Cogan syndrome as an autoimmune vasculitis.
  - reference: PMID:24979832
    reference_title: "Cogan's syndrome: anti-Hsp70 antibodies are a serological marker in the typical form."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Cogan's syndrome (CS) is a rare autoimmune vasculitis characterized by ocular inflammation and sensorineural hearing loss."
    explanation: Review links autoimmune vasculitis to ocular and audiovestibular manifestations.
  downstream:
  - target: Vasculitis
    description: Systemic immune-mediated vascular inflammation manifests as clinically apparent vasculitis.
    causal_link_type: DIRECT
  - target: Large vessel vasculitis
    description: Vascular inflammation can involve the aorta and other large vessels.
    causal_link_type: DIRECT
  - target: Medium vessel vasculitis
    description: Vascular inflammation can involve medium-caliber arteries.
    causal_link_type: DIRECT
  - target: Arteritis
    description: Arterial wall inflammation, including coronary arteritis, can occur.
    causal_link_type: DIRECT
  - target: Aortitis
    description: Aortic-wall inflammation is a large-vessel manifestation of systemic vasculitis.
    causal_link_type: DIRECT
  - target: Retinal vasculitis
    description: Vasculitic involvement of retinal vessels in atypical ocular disease.
    causal_link_type: DIRECT
  - target: Episcleritis
    description: Inflammation of episcleral vasculature as an ocular manifestation.
    causal_link_type: DIRECT
  - target: Uveitis
    description: Ocular immune-mediated inflammation manifesting as uveitis in atypical disease.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - ocular immune-mediated inflammation
  - target: Panuveitis
    description: Diffuse intraocular immune-mediated inflammation manifesting as panuveitis.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - ocular immune-mediated inflammation
mechanistic_hypotheses:
- hypothesis_group_id: molecular_mimicry_postinfectious
  hypothesis_label: Post-infectious molecular mimicry model
  status: EMERGING
  description: >-
    The leading model holds that an antecedent infection triggers an autoimmune
    response via molecular mimicry: an immunodominant peptide recognized by patient
    IgG shares sequence similarity with the reovirus III major core protein and the
    SSA/Ro autoantigen, generating autoantibodies that cross-react with inner-ear
    and endothelial self-antigens (CD148/DEP-1, connexin 26) and drive tissue injury.
  evidence:
  - reference: PMID:12354474
    reference_title: "Autoantibodies to inner ear and endothelial antigens in Cogan's syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We identified an immunodominant peptide that shows similarity with autoantigens such as SSA/Ro and with the reovirus III major core protein"
    explanation: Peptide-library identification of a mimicry epitope shared with a reovirus protein and SSA/Ro is the molecular basis for the post-infectious mimicry model.
  - reference: PMID:22846458
    reference_title: "Cogan's syndrome: an autoimmune inner ear disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Infection, but primarily autoimmunity, may play contributing roles in the pathogenesis of this disease."
    explanation: Review supports infection as a contributing trigger while emphasizing that pathogenesis remains incompletely defined, justifying EMERGING status.
  notes: >-
    Status EMERGING because the pathogenesis is described in the literature as
    unknown; the mimicry epitope and animal passive-transfer data are the strongest
    mechanistic support but a definitive infectious trigger is unproven. The
    trigger-level downstream edges on the "Molecular mimicry and autoantibody
    generation" pathophysiology node opt into this hypothesis group.
histopathology:
- name: Endolymphatic hydrops
  description: Histology of the temporal bone shows endolymphatic hydrops.
  evidence:
  - reference: PMID:38973571
    reference_title: "Temporal Bone Histopathology of Atypical Cogan Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "findings revealed endolymphatic hydrops"
    explanation: Temporal bone histopathology demonstrates endolymphatic hydrops in atypical Cogan syndrome.
- name: Inner ear degenerative changes
  description: Degenerative changes are seen in multiple inner ear structures.
  evidence:
  - reference: PMID:38973571
    reference_title: "Temporal Bone Histopathology of Atypical Cogan Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "degenerative changes in various parts of the inner ear"
    explanation: Temporal bone histology shows degenerative changes across inner ear structures.
phenotypes:
- name: Keratitis
  category: Ophthalmologic
  frequency: FREQUENT
  description: Interstitial keratitis in typical Cogan syndrome.
  phenotype_term:
    preferred_term: Keratitis
    term:
      id: HP:0000491
      label: Keratitis
  evidence:
  - reference: PMID:24979832
    reference_title: "Cogan's syndrome: anti-Hsp70 antibodies are a serological marker in the typical form."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: '"typical" form with non-syphilitic interstitial keratitis and audiovestibular symptoms'
    explanation: Typical Cogan syndrome includes interstitial keratitis.
  - reference: PMID:39328241
    reference_title: "A case report of Cogan's syndrome with recurrent coronary stenosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "history of non-syphilis keratitis"
    explanation: Case report documents keratitis in Cogan syndrome.
  - reference: PMID:36502531
    reference_title: "Report of 2 pediatric cases with atypical Cogan's syndrome and a systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Cogan's syndrome (CS) is a rare inflammatory disease characterized by interstitial keratitis or uveitis, vestibular impairment, and progressive hearing loss, commonly bilateral."
    explanation: Pediatric review notes interstitial keratitis as a defining manifestation.
- name: Uveitis
  category: Ophthalmologic
  frequency: OCCASIONAL
  phenotype_term:
    preferred_term: Uveitis
    term:
      id: HP:0000554
      label: Uveitis
  evidence:
  - reference: PMID:36502531
    reference_title: "Report of 2 pediatric cases with atypical Cogan's syndrome and a systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Cogan's syndrome (CS) is a rare inflammatory disease characterized by interstitial keratitis or uveitis, vestibular impairment, and progressive hearing loss, commonly bilateral."
    explanation: Pediatric review highlights uveitis as a core ocular manifestation.
- name: Sensorineural hearing impairment
  category: Auditory
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Sensorineural hearing impairment
    term:
      id: HP:0000407
      label: Sensorineural hearing impairment
  evidence:
  - reference: PMID:24979832
    reference_title: "Cogan's syndrome: anti-Hsp70 antibodies are a serological marker in the typical form."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Cogan's syndrome (CS) is a rare autoimmune vasculitis characterized by ocular inflammation and sensorineural hearing loss."
    explanation: Review notes sensorineural hearing loss as a defining feature.
  - reference: PMID:41473897
    reference_title: "Cogan's Syndrome: Complex Diagnostics, Treatment, and Results of Hearing Rehabilitation in Long-Term Follow-Up-Case Series."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Bilateral, asymmetric hearing impairment manifested as sudden sensorineural hearing loss"
    explanation: Case series reports sudden sensorineural hearing loss in Cogan syndrome.
  - reference: PMID:40866103
    reference_title: "Atypical Cogan's syndrome with delayed auditory and ocular manifestations."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "remote history of chronic iritis and bilateral sensorineural hearing loss"
    explanation: Case report documents bilateral sensorineural hearing loss in atypical Cogan syndrome.
  - reference: PMID:39280458
    reference_title: "A Case of Bilateral Retinal Vasculitis in Atypical Cogan Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Hearing tests revealed impaired hearing in both ears."
    explanation: Case report shows bilateral hearing impairment in atypical Cogan syndrome.
  - reference: PMID:36502531
    reference_title: "Report of 2 pediatric cases with atypical Cogan's syndrome and a systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Cogan's syndrome (CS) is a rare inflammatory disease characterized by interstitial keratitis or uveitis, vestibular impairment, and progressive hearing loss, commonly bilateral."
    explanation: Pediatric review emphasizes progressive hearing loss as a defining feature.
- name: Vertigo
  category: Neurologic
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Vertigo
    term:
      id: HP:0002321
      label: Vertigo
  evidence:
  - reference: PMID:39455380
    reference_title: "French protocol for diagnosis and management of Cogan's syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "It is characterised by the sudden onset of continuous rotational vertigo associated with tinnitus"
    explanation: French protocol describes sudden continuous rotational vertigo in cochleo-vestibular involvement.
  - reference: PMID:39543746
    reference_title: "Atypical Cogan syndrome: a case report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "isolated and fluctuating audiovestibular Ménière-like symptoms"
    explanation: Case report notes Menière-like audiovestibular symptoms consistent with vertigo.
  - reference: PMID:39280458
    reference_title: "A Case of Bilateral Retinal Vasculitis in Atypical Cogan Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Inner ear symptoms include sensorineural hearing loss, rotatory vertigo, and tinnitus"
    explanation: Case report summary reiterates rotatory vertigo as an inner ear symptom.
- name: Tinnitus
  category: Auditory
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Tinnitus
    term:
      id: HP:0000360
      label: Tinnitus
  evidence:
  - reference: PMID:39455380
    reference_title: "French protocol for diagnosis and management of Cogan's syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "It is characterised by the sudden onset of continuous rotational vertigo associated with tinnitus"
    explanation: French protocol notes tinnitus as part of cochleo-vestibular involvement.
  - reference: PMID:39543746
    reference_title: "Atypical Cogan syndrome: a case report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "isolated and fluctuating audiovestibular Ménière-like symptoms"
    explanation: Case report describes Menière-like symptoms consistent with tinnitus.
  - reference: PMID:39280458
    reference_title: "A Case of Bilateral Retinal Vasculitis in Atypical Cogan Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Inner ear symptoms include sensorineural hearing loss, rotatory vertigo, and tinnitus"
    explanation: Case report summary includes tinnitus among inner ear symptoms.
- name: Absent vestibular function
  category: Neurologic
  frequency: OCCASIONAL
  phenotype_term:
    preferred_term: Absent vestibular function
    term:
      id: HP:0008555
      label: Absent vestibular function
  evidence:
  - reference: PMID:41473897
    reference_title: "Cogan's Syndrome: Complex Diagnostics, Treatment, and Results of Hearing Rehabilitation in Long-Term Follow-Up-Case Series."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "all patients experienced loss of bilateral vestibular function"
    explanation: Case series reports loss of bilateral vestibular function in Cogan syndrome.
  - reference: PMID:39268327
    reference_title: "A Pediatric Case of Cogan's Syndrome With Internal Otitis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "bilateral vestibular dysfunction"
    explanation: Pediatric case report documents bilateral vestibular dysfunction.
  - reference: PMID:36502531
    reference_title: "Report of 2 pediatric cases with atypical Cogan's syndrome and a systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Cogan's syndrome (CS) is a rare inflammatory disease characterized by interstitial keratitis or uveitis, vestibular impairment, and progressive hearing loss, commonly bilateral."
    explanation: Pediatric review notes vestibular impairment as a key manifestation.
- name: Episcleritis
  category: Ophthalmologic
  frequency: OCCASIONAL
  phenotype_term:
    preferred_term: Episcleritis
    term:
      id: HP:0100534
      label: Episcleritis
  evidence:
  - reference: PMID:12354474
    reference_title: "Autoantibodies to inner ear and endothelial antigens in Cogan's syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "characterised by sensorineural hearing loss, episcleritis, and vasculitis."
    explanation: Study lists episcleritis as a characteristic clinical feature.
- name: Panuveitis
  category: Ophthalmologic
  frequency: OCCASIONAL
  phenotype_term:
    preferred_term: Panuveitis
    term:
      id: HP:0012121
      label: Panuveitis
  evidence:
  - reference: PMID:39268327
    reference_title: "A Pediatric Case of Cogan's Syndrome With Internal Otitis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The patient had panuveitis"
    explanation: Pediatric case report documents panuveitis in Cogan syndrome.
- name: Retinal vasculitis
  category: Ophthalmologic
  frequency: OCCASIONAL
  phenotype_term:
    preferred_term: Retinal vasculitis
    term:
      id: HP:0025188
      label: Retinal vasculitis
  evidence:
  - reference: PMID:39280458
    reference_title: "A Case of Bilateral Retinal Vasculitis in Atypical Cogan Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Uveitis with retinal vasculitis was observed in both eyes"
    explanation: Case report documents bilateral retinal vasculitis in atypical Cogan syndrome.
- name: Aortic regurgitation
  category: Cardiovascular
  frequency: VERY_RARE
  phenotype_term:
    preferred_term: Aortic regurgitation
    term:
      id: HP:0001659
      label: Aortic regurgitation
  evidence:
  - reference: PMID:40843044
    reference_title: "Was an aortic valve replacement with a mechanical valve the right option all along? Cogan's syndrome with recurrent aortic regurgitation: a case of evolving surgical decisions."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "presented with newly diagnosed, severe aortic regurgitation (AR)"
    explanation: Case report documents severe aortic regurgitation in Cogan syndrome.
- name: Aortitis
  phenotype_term:
    preferred_term: Aortitis
    term:
      id: HP:6001461
      label: Aortitis
  category: Cardiovascular
  frequency: OCCASIONAL
  description: Aortic wall inflammation has been reported with Cogan syndrome.
  evidence:
  - reference: PMID:29489984
    reference_title: "Cogan's syndrome - A rare aortitis, difficult to diagnose but with therapeutic potential."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The inflammation of aortic wall, named aortitis, is a rare condition that can be caused by a number of pathologies, mainly inflammatory or infectious in nature. In this context, the occurrence of combined audiovestibular and/or ocular manifestations eventually led to the diagnosis of Cogan's syndrome"
    explanation: Case report ties aortitis to Cogan syndrome diagnosis.
  - reference: PMID:36502531
    reference_title: "Report of 2 pediatric cases with atypical Cogan's syndrome and a systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Also, aortic involvement was present in 19.5% of patients in the literature."
    explanation: Pediatric systematic review reports aortic involvement frequency.
  sequelae:
  - target: Aortic regurgitation
    description: Aortic-root and valve involvement from aortitis can lead to aortic regurgitation.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - aortic root dilation
    - valvular involvement
- name: Coronary artery stenosis
  category: Cardiovascular
  frequency: VERY_RARE
  phenotype_term:
    preferred_term: Coronary artery stenosis
    term:
      id: HP:0005145
      label: Coronary artery stenosis
  evidence:
  - reference: PMID:39328241
    reference_title: "A case report of Cogan's syndrome with recurrent coronary stenosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "recurrent coronary artery stenosis"
    explanation: Case report describes recurrent coronary artery stenosis in Cogan syndrome.
  sequelae:
  - target: Acute coronary syndrome
    description: Coronary stenosis from coronaritis can precipitate acute coronary syndrome.
    causal_link_type: DIRECT
- name: Vasculitis
  category: Cardiovascular
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Vasculitis
    term:
      id: HP:0002633
      label: Vasculitis
  evidence:
  - reference: PMID:22846458
    reference_title: "Cogan's syndrome: an autoimmune inner ear disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Approximately 70% of patients have systemic disease, of which vasculitis is considered the pathological mechanism."
    explanation: Review reports frequent systemic vasculitis.
  - reference: PMID:12354474
    reference_title: "Autoantibodies to inner ear and endothelial antigens in Cogan's syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "characterised by sensorineural hearing loss, episcleritis, and vasculitis."
    explanation: Study includes vasculitis among defining features.
  - reference: PMID:27330475
    reference_title: "Cogan syndrome with severe medium and large vessel vasculitis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Almost half of patients develop systemic manifestations."
    explanation: Case report notes systemic manifestations, consistent with vasculitic disease.
- name: Large vessel vasculitis
  category: Cardiovascular
  frequency: OCCASIONAL
  phenotype_term:
    preferred_term: Large vessel vasculitis
    term:
      id: HP:0005310
      label: Large vessel vasculitis
  evidence:
  - reference: PMID:28583785
    reference_title: "Late-onset Cogan's syndrome associated with large-vessel vasculitis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "late-onset Cogan's syndrome associated with a large-vessel vasculitis."
    explanation: Case report documents large-vessel vasculitis in Cogan syndrome.
  - reference: PMID:29489984
    reference_title: "Cogan's syndrome - A rare aortitis, difficult to diagnose but with therapeutic potential."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The inflammation of aortic wall, named aortitis, is a rare condition"
    explanation: Aortitis is a large-vessel inflammatory manifestation reported in Cogan syndrome.
  - reference: PMID:27330475
    reference_title: "Cogan syndrome with severe medium and large vessel vasculitis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "severe medium and large vessel vasculitis"
    explanation: Case report describes severe large-vessel vasculitis in Cogan syndrome.
- name: Medium vessel vasculitis
  category: Cardiovascular
  frequency: OCCASIONAL
  phenotype_term:
    preferred_term: Medium vessel vasculitis
    term:
      id: HP:6000658
      label: Medium vessel vasculitis
  evidence:
  - reference: PMID:27330475
    reference_title: "Cogan syndrome with severe medium and large vessel vasculitis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "severe medium and large vessel vasculitis"
    explanation: Case report documents medium-vessel vasculitis as a systemic manifestation.
- name: Arteritis
  category: Cardiovascular
  frequency: OCCASIONAL
  description: Systemic arteritis with coronary involvement has been reported.
  phenotype_term:
    preferred_term: Arteritis
    term:
      id: HP:0012089
      label: Arteritis
  evidence:
  - reference: PMID:39999281
    reference_title: "The Role of 18 F-FDG PET/CT Combined With MPI in Cogan's Syndrome With Multiple Arteritis and Coronary Involvement: A Case Report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "multiple arteritis involving the coronary artery"
    explanation: Case report describes multiple arteritis with coronary involvement in Cogan syndrome.
  - reference: PMID:40054904
    reference_title: "Managing Complex Coronary Revascularization of Acute Coronary Syndrome During Cogan Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Cogan syndrome, a rare multisystemic autoimmune vasculitis, can result in coronaritis"
    explanation: Case report notes coronaritis in Cogan syndrome.
  - reference: PMID:39328241
    reference_title: "A case report of Cogan's syndrome with recurrent coronary stenosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Cogan's syndrome (CS) is recognized as a form of variable vasculitis."
    explanation: Case report reiterates vasculitis classification in Cogan syndrome.
  sequelae:
  - target: Coronary artery stenosis
    description: Coronary arteritis can produce coronary artery stenosis.
    causal_link_type: DIRECT
- name: Acute coronary syndrome
  category: Cardiovascular
  frequency: VERY_RARE
  description: Acute coronary syndrome can occur due to coronaritis in systemic vasculitis.
  phenotype_term:
    preferred_term: Acute coronary syndrome
    term:
      id: HP:0033678
      label: Acute coronary syndrome
  evidence:
  - reference: PMID:40054904
    reference_title: "Managing Complex Coronary Revascularization of Acute Coronary Syndrome During Cogan Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "can result in coronaritis and precipitate acute coronary syndrome."
    explanation: Case report describes acute coronary syndrome in Cogan syndrome with coronaritis.
  - reference: PMID:39007044
    reference_title: "Anterior STEMI in a 25-year-old with Cogan syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "anterior ST-elevation myocardial infarction"
    explanation: Case report documents STEMI as an acute coronary syndrome manifestation in Cogan syndrome.
diagnosis:
- name: FDG PET/CT for arteritis evaluation
  description: FDG PET/CT can identify arteritis with coronary involvement and guide anti-inflammatory management.
  diagnosis_term:
    preferred_term: positron emission tomography procedure
    term:
      id: MAXO:0000137
      label: positron emission tomography procedure
  evidence:
  - reference: PMID:39999281
    reference_title: "The Role of 18 F-FDG PET/CT Combined With MPI in Cogan's Syndrome With Multiple Arteritis and Coronary Involvement: A Case Report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "18 F-FDG PET/CT showed multiple arteritis involving the coronary artery"
    explanation: Case report demonstrates PET/CT detection of arteritis with coronary involvement.
  - reference: PMID:39328241
    reference_title: "A case report of Cogan's syndrome with recurrent coronary stenosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Positron emission tomography/computed tomography revealed an elevated uptake of (18)F-fluorodeoxyglucose"
    explanation: Case report shows FDG PET/CT uptake in large vessels during Cogan syndrome.
differential_diagnoses:
- name: Meniere disease
  description: Audiovestibular symptoms can mimic Meniere disease.
  disease_term:
    preferred_term: Meniere disease
    term:
      id: MONDO:0007972
      label: Meniere disease
  evidence:
  - reference: PMID:22846458
    reference_title: "Cogan's syndrome: an autoimmune inner ear disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "audiovestibular symptoms similar to those of Meniere's syndrome."
    explanation: Review notes audiovestibular symptoms resembling Meniere disease, supporting it as a differential.
- name: Takayasu arteritis
  description: Large-vessel vasculitis can overlap with systemic Cogan syndrome.
  disease_term:
    preferred_term: Takayasu arteritis
    term:
      id: MONDO:0017991
      label: Takayasu arteritis
  evidence:
  - reference: PMID:39455380
    reference_title: "French protocol for diagnosis and management of Cogan's syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Association with other autoimmune diseases, particularly other forms of vasculitis such as polyarteritis nodosa or Takayasu's arteritis, is possible."
    explanation: Protocol notes association with Takayasu arteritis.
- name: Polyarteritis nodosa
  description: Medium-vessel vasculitis can be associated with Cogan syndrome.
  disease_term:
    preferred_term: polyarteritis nodosa
    term:
      id: MONDO:0019170
      label: polyarteritis nodosa
  evidence:
  - reference: PMID:39455380
    reference_title: "French protocol for diagnosis and management of Cogan's syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Association with other autoimmune diseases, particularly other forms of vasculitis such as polyarteritis nodosa or Takayasu's arteritis, is possible."
    explanation: Protocol notes association with polyarteritis nodosa.
biochemical: []
genetic: []
environmental: []
treatments:
- name: Corticosteroid therapy
  description: Corticosteroids are first-line therapy for Cogan syndrome.
  evidence:
  - reference: PMID:22846458
    reference_title: "Cogan's syndrome: an autoimmune inner ear disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Corticosteroids are the first line of treatment"
    explanation: Review identifies corticosteroids as first-line therapy.
  - reference: PMID:36502531
    reference_title: "Report of 2 pediatric cases with atypical Cogan's syndrome and a systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Although glucocorticoids are fundamental treatment options"
    explanation: Pediatric review highlights glucocorticoids as fundamental therapy.
  treatment_term:
    preferred_term: systemic corticosteroid therapy
    term:
      id: NCIT:C122080
      label: Systemic Corticosteroid Therapy
    therapeutic_agent:
    - preferred_term: prednisone
      term:
        id: CHEBI:8382
        label: prednisone
- name: Immunosuppressive therapy
  description: Immunosuppressive agents are used for refractory or systemic disease.
  evidence:
  - reference: PMID:41473897
    reference_title: "Cogan's Syndrome: Complex Diagnostics, Treatment, and Results of Hearing Rehabilitation in Long-Term Follow-Up-Case Series."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "immunosuppressive therapy (methotrexate, cyclophosphamide, cyclosporin A)"
    explanation: Case series reports use of multiple immunosuppressive agents.
  - reference: PMID:40866103
    reference_title: "Atypical Cogan's syndrome with delayed auditory and ocular manifestations."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "she was started on systemic corticosteroids with rapid improvement in visual acuity and resolution of symptoms."
    explanation: Case report illustrates systemic therapy response in atypical Cogan syndrome.
  - reference: PMID:36502531
    reference_title: "Report of 2 pediatric cases with atypical Cogan's syndrome and a systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "treated with corticosteroids and methotrexate."
    explanation: Pediatric cases used methotrexate as an immunosuppressive agent.
  treatment_term:
    preferred_term: immunosuppressive therapy
    term:
      id: MAXO:0000297
      label: immune suppressant agent therapy
    therapeutic_agent:
    - preferred_term: methotrexate
      term:
        id: CHEBI:44185
        label: methotrexate
    - preferred_term: cyclophosphamide
      term:
        id: CHEBI:4027
        label: cyclophosphamide
    - preferred_term: cyclosporin A
      term:
        id: CHEBI:4031
        label: cyclosporin A
- name: TNF-alpha inhibitor therapy
  description: TNF-alpha blockers represent a novel immunosuppressive option.
  evidence:
  - reference: PMID:22846458
    reference_title: "Cogan's syndrome: an autoimmune inner ear disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Tumour necrosis factor (TNF)-alpha blockers are a category of immunosuppressive agents representing a recent novel therapeutic option in Cogan's syndrome."
    explanation: Review notes TNF-alpha blockers as a therapeutic option.
  - reference: PMID:39455380
    reference_title: "French protocol for diagnosis and management of Cogan's syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Combination with anti-TNF therapy should be promptly discussed."
    explanation: Protocol recommends prompt consideration of anti-TNF therapy.
  - reference: PMID:41473897
    reference_title: "Cogan's Syndrome: Complex Diagnostics, Treatment, and Results of Hearing Rehabilitation in Long-Term Follow-Up-Case Series."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "biological treatment (infliximab, adalimumab)"
    explanation: Case series reports biologic anti-TNF agents used in Cogan syndrome.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
- name: Cochlear device implantation
  description: Cochlear implantation is used for hearing rehabilitation in severe hearing loss.
  evidence:
  - reference: PMID:41473897
    reference_title: "Cogan's Syndrome: Complex Diagnostics, Treatment, and Results of Hearing Rehabilitation in Long-Term Follow-Up-Case Series."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "four patients were treated with cochlear implantation and achieved long-term stable speech perception."
    explanation: Case series reports cochlear implantation with stable long-term outcomes.
  - reference: PMID:36502531
    reference_title: "Report of 2 pediatric cases with atypical Cogan's syndrome and a systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "One patient had a cochlear implant"
    explanation: Pediatric case report includes cochlear implantation.
  treatment_term:
    preferred_term: cochlear device implantation
    term:
      id: MAXO:0009025
      label: cochlear device implantation
datasets: []
clinical_trials:
- name: NCT05168475
  description: >-
    BIOVAS — a randomised, double-blind, placebo-controlled, modified-crossover
    trial of biologic therapy (including rituximab, tocilizumab, and infliximab)
    for refractory primary non-ANCA-associated vasculitis in adults and children.
    Cogan syndrome is one of the enrolled non-ANCA-associated vasculitides.
  phase: PHASE_II
  status: TERMINATED
  target_phenotypes:
  - preferred_term: Vasculitis
    term:
      id: HP:0002633
      label: Vasculitis
  evidence:
  - reference: clinicaltrials:NCT05168475
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The trial will include patients with Non-ANCA-associated vasculitis (NAAV)"
    explanation: BIOVAS enrolls non-ANCA-associated vasculitides, with Cogan Syndrome listed among the trial's conditions, evaluating biologic therapy for refractory disease.
  notes: >-
    Listed as TERMINATED on ClinicalTrials.gov (NIHR withdrawal of funding).
    Cogan Syndrome appears in the trial's registered condition list alongside
    giant cell arteritis, Takayasu arteritis, and other non-ANCA vasculitides.
references:
- reference: DOI:10.1007/s00405-024-08878-5
  title: 'Audiovestibular outcomes in adult patients with cogan syndrome: a systematic review'
  found_in:
  - Cogan_Syndrome-deep-research-falcon.md
  findings:
  - statement: To determine factors associated with steroid responsiveness and efficacy of biologic disease-modifying anti-rheumatic (DMARD) use in patients with Cogan Syndrome (CS).
    supporting_text: To determine factors associated with steroid responsiveness and efficacy of biologic disease-modifying anti-rheumatic (DMARD) use in patients with Cogan Syndrome (CS).
    evidence:
    - reference: DOI:10.1007/s00405-024-08878-5
      reference_title: 'Audiovestibular outcomes in adult patients with cogan syndrome: a systematic review'
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: To determine factors associated with steroid responsiveness and efficacy of biologic disease-modifying anti-rheumatic (DMARD) use in patients with Cogan Syndrome (CS).
      explanation: Deep research cited this publication as relevant literature for Cogan Syndrome.
- reference: DOI:10.1155/2018/1498640
  title: 'Autoimmune Inner Ear Disease: Immune Biomarkers, Audiovestibular Aspects, and Therapeutic Modalities of Cogan’s Syndrome'
  found_in:
  - Cogan_Syndrome-deep-research-falcon.md
  findings:
  - statement: Cogan’s syndrome (CS) is a rare autoimmune disorder characterized by audiovestibular dysfunction and ocular inflammation.
    supporting_text: Cogan’s syndrome (CS) is a rare autoimmune disorder characterized by audiovestibular dysfunction and ocular inflammation.
    evidence:
    - reference: DOI:10.1155/2018/1498640
      reference_title: 'Autoimmune Inner Ear Disease: Immune Biomarkers, Audiovestibular Aspects, and Therapeutic Modalities of Cogan’s Syndrome'
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: Cogan’s syndrome (CS) is a rare autoimmune disorder characterized by audiovestibular dysfunction and ocular inflammation.
      explanation: Deep research cited this publication as relevant literature for Cogan Syndrome.
- reference: DOI:10.1159/000551227
  title: 'Atypical Cogan’s Syndrome Presenting as Anterior Scleritis: Case Report'
  found_in:
  - Cogan_Syndrome-deep-research-falcon.md
  findings:
  - statement: Cogan’s syndrome is a rare autoimmune vasculitis characterized by ocular inflammation and audiovestibular dysfunction, with the atypical form presenting with inflammatory ocular disease other than interstitial keratitis.
    supporting_text: Cogan’s syndrome is a rare autoimmune vasculitis characterized by ocular inflammation and audiovestibular dysfunction, with the atypical form presenting with inflammatory ocular disease other than interstitial keratitis.
    evidence:
    - reference: DOI:10.1159/000551227
      reference_title: 'Atypical Cogan’s Syndrome Presenting as Anterior Scleritis: Case Report'
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: Cogan’s syndrome is a rare autoimmune vasculitis characterized by ocular inflammation and audiovestibular dysfunction, with the atypical form presenting with inflammatory ocular disease other than interstitial keratitis.
      explanation: Deep research cited this publication as relevant literature for Cogan Syndrome.
- reference: DOI:10.1186/s12886-023-02966-6
  title: 'Cogan’s syndrome is more than just keratitis: a case-based literature review'
  found_in:
  - Cogan_Syndrome-deep-research-falcon.md
  findings:
  - statement: Cogan's syndrome (CS) is a rare autoimmune disorder characterized by non-syphilitic interstitial keratitis (IK) and Menière-like cochlear vestibular symptoms, which may also have systemic effects.
    supporting_text: Cogan's syndrome (CS) is a rare autoimmune disorder characterized by non-syphilitic interstitial keratitis (IK) and Menière-like cochlear vestibular symptoms, which may also have systemic effects.
    evidence:
    - reference: DOI:10.1186/s12886-023-02966-6
      reference_title: 'Cogan’s syndrome is more than just keratitis: a case-based literature review'
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: Cogan's syndrome (CS) is a rare autoimmune disorder characterized by non-syphilitic interstitial keratitis (IK) and Menière-like cochlear vestibular symptoms, which may also have systemic effects.
      explanation: Deep research cited this publication as relevant literature for Cogan Syndrome.
- reference: DOI:10.1186/s12969-023-00830-x
  title: Paediatric Cogan´s syndrome - review of literature, case report and practical approach to diagnosis and management
  found_in:
  - Cogan_Syndrome-deep-research-falcon.md
  findings:
  - statement: Cogan´s syndrome is a rare, presumed autoimmune vasculitis of various vessels characterized by interstitial keratitis and vestibular impairment accompanied by sensorineural hearing loss.
    supporting_text: Cogan´s syndrome is a rare, presumed autoimmune vasculitis of various vessels characterized by interstitial keratitis and vestibular impairment accompanied by sensorineural hearing loss.
    evidence:
    - reference: DOI:10.1186/s12969-023-00830-x
      reference_title: Paediatric Cogan´s syndrome - review of literature, case report and practical approach to diagnosis and management
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: Cogan´s syndrome is a rare, presumed autoimmune vasculitis of various vessels characterized by interstitial keratitis and vestibular impairment accompanied by sensorineural hearing loss.
      explanation: Deep research cited this publication as relevant literature for Cogan Syndrome.
📚

References & Deep Research

References

5
DOI:10.1007/s00405-024-08878-5
Audiovestibular outcomes in adult patients with cogan syndrome: a systematic review
1 finding
To determine factors associated with steroid responsiveness and efficacy of biologic disease-modifying anti-rheumatic (DMARD) use in patients with Cogan Syndrome (CS).
"To determine factors associated with steroid responsiveness and efficacy of biologic disease-modifying anti-rheumatic (DMARD) use in patients with Cogan Syndrome (CS)."
Show evidence (1 reference)
DOI:10.1007/s00405-024-08878-5 SUPPORT Human Clinical
"To determine factors associated with steroid responsiveness and efficacy of biologic disease-modifying anti-rheumatic (DMARD) use in patients with Cogan Syndrome (CS)."
Deep research cited this publication as relevant literature for Cogan Syndrome.
DOI:10.1155/2018/1498640
Autoimmune Inner Ear Disease: Immune Biomarkers, Audiovestibular Aspects, and Therapeutic Modalities of Cogan’s Syndrome
1 finding
Cogan’s syndrome (CS) is a rare autoimmune disorder characterized by audiovestibular dysfunction and ocular inflammation.
"Cogan’s syndrome (CS) is a rare autoimmune disorder characterized by audiovestibular dysfunction and ocular inflammation."
Show evidence (1 reference)
DOI:10.1155/2018/1498640 SUPPORT Human Clinical
"Cogan’s syndrome (CS) is a rare autoimmune disorder characterized by audiovestibular dysfunction and ocular inflammation."
Deep research cited this publication as relevant literature for Cogan Syndrome.
DOI:10.1159/000551227
Atypical Cogan’s Syndrome Presenting as Anterior Scleritis: Case Report
1 finding
Cogan’s syndrome is a rare autoimmune vasculitis characterized by ocular inflammation and audiovestibular dysfunction, with the atypical form presenting with inflammatory ocular disease other than interstitial keratitis.
"Cogan’s syndrome is a rare autoimmune vasculitis characterized by ocular inflammation and audiovestibular dysfunction, with the atypical form presenting with inflammatory ocular disease other than interstitial keratitis."
Show evidence (1 reference)
DOI:10.1159/000551227 SUPPORT Human Clinical
"Cogan’s syndrome is a rare autoimmune vasculitis characterized by ocular inflammation and audiovestibular dysfunction, with the atypical form presenting with inflammatory ocular disease other than interstitial keratitis."
Deep research cited this publication as relevant literature for Cogan Syndrome.
DOI:10.1186/s12886-023-02966-6
Cogan’s syndrome is more than just keratitis: a case-based literature review
1 finding
Cogan's syndrome (CS) is a rare autoimmune disorder characterized by non-syphilitic interstitial keratitis (IK) and Menière-like cochlear vestibular symptoms, which may also have systemic effects.
"Cogan's syndrome (CS) is a rare autoimmune disorder characterized by non-syphilitic interstitial keratitis (IK) and Menière-like cochlear vestibular symptoms, which may also have systemic effects."
Show evidence (1 reference)
DOI:10.1186/s12886-023-02966-6 SUPPORT Human Clinical
"Cogan's syndrome (CS) is a rare autoimmune disorder characterized by non-syphilitic interstitial keratitis (IK) and Menière-like cochlear vestibular symptoms, which may also have systemic effects."
Deep research cited this publication as relevant literature for Cogan Syndrome.
DOI:10.1186/s12969-023-00830-x
Paediatric Cogan´s syndrome - review of literature, case report and practical approach to diagnosis and management
1 finding
Cogan´s syndrome is a rare, presumed autoimmune vasculitis of various vessels characterized by interstitial keratitis and vestibular impairment accompanied by sensorineural hearing loss.
"Cogan´s syndrome is a rare, presumed autoimmune vasculitis of various vessels characterized by interstitial keratitis and vestibular impairment accompanied by sensorineural hearing loss."
Show evidence (1 reference)
DOI:10.1186/s12969-023-00830-x SUPPORT Human Clinical
"Cogan´s syndrome is a rare, presumed autoimmune vasculitis of various vessels characterized by interstitial keratitis and vestibular impairment accompanied by sensorineural hearing loss."
Deep research cited this publication as relevant literature for Cogan Syndrome.

Deep Research

1
Falcon ▸
Cogan Syndrome (Autoimmune/Immune‑mediated Vasculitis) — Disease Characteristics Research Report
Edison Scientific Literature 24 citations 2026-05-08T13:25:55.412870

Cogan Syndrome (Autoimmune/Immune‑mediated Vasculitis) — Disease Characteristics Research Report

Executive summary

Cogan syndrome (CS) is a rare immune‑mediated disorder classically defined by inflammatory ocular disease (especially non‑syphilitic interstitial keratitis) together with audiovestibular dysfunction (often Ménière‑like episodes and progressive sensorineural hearing loss), with frequent systemic vasculitic involvement that can include potentially life‑threatening aortitis. (wang2023cogan’ssyndromeis pages 1-2, espinoza2020cogan’ssyndromeclinical pages 1-3, tayershifman2014coganssyndrome—clinicalguidelines pages 2-3)

Recent clinically actionable findings include (i) continued emphasis that diagnosis is clinical and by exclusion, with no single confirmatory biomarker; (ii) increasing use of biologics (especially anti‑TNF agents such as infliximab) for steroid‑refractory disease; and (iii) early hearing rehabilitation (cochlear implantation) when profound hearing loss occurs due to risk of intracochlear fibrosis/neo‑ossification. (espinoza2020cogan’ssyndromeclinical pages 4-5, shamriz2018autoimmuneinnerear pages 1-2, rucklova2023paediatriccogan´ssyndrome pages 2-4)

1. Disease Information

1.1 Overview / definition

Core concept: CS is a “variable vessel vasculitis” phenotype with primary involvement of the eye and inner ear, and with systemic vasculitis in a substantial subset. (ince2023coganssyndrome pages 1-2, tayershifman2014coganssyndrome—clinicalguidelines pages 2-3)

Typical vs atypical CS (2‑year rule): - Typical CS is commonly defined by non‑syphilitic interstitial keratitis plus audiovestibular symptoms occurring within 2 years. (wang2023cogan’ssyndromeis pages 1-2) - Atypical CS includes (a) ocular inflammation other than interstitial keratitis and/or (b) >2‑year delay between ocular and audiovestibular manifestations, and is often described as more frequently systemic. (mendes2026atypicalcogan’ssyndrome pages 2-2, mendes2026atypicalcogan’ssyndrome pages 2-3)

Direct abstract quotes supporting definition: - “Cogan’s syndrome (CS) is a rare autoimmune disorder characterized by audiovestibular dysfunction and ocular inflammation.” (Shamriz 2018, published 2018-04-23; https://doi.org/10.1155/2018/1498640) (shamriz2018autoimmuneinnerear pages 1-2) - “Cogan´s syndrome is a rare, presumed autoimmune vasculitis of various vessels characterized by interstitial keratitis and vestibular impairment accompanied by sensorineural hearing loss.” (Rücklová 2023, published 2023-06; https://doi.org/10.1186/s12969-023-00830-x) (rucklova2023paediatriccogan´ssyndrome pages 2-4)

1.2 Key identifiers and controlled vocabulary

Note: In the evidence retrieved here, authoritative identifier mappings (e.g., MONDO, Orphanet ORPHA code, ICD‑10/ICD‑11, MeSH) were not directly available as primary sources. Therefore, IDs are not asserted in this report.

Synonyms / alternative names (used in clinical literature): - Cogan’s syndrome - Typical Cogan syndrome - Atypical Cogan syndrome - Cogan syndrome with aortitis / systemic vasculitis (wang2023cogan’ssyndromeis pages 1-2, tayershifman2014coganssyndrome—clinicalguidelines pages 2-3)

1.3 Evidence sources: individual vs aggregated

Because CS is rare, most treatment and phenotype evidence remains derived from case reports/series and retrospective cohorts, including systematic reviews that largely pool case reports. (marrerogonzalez2025audiovestibularoutcomesin pages 1-2, espinoza2020cogan’ssyndromeclinical pages 4-5)

2. Etiology

2.1 Disease causal factors (current understanding)

Primary etiology: CS is widely regarded as autoimmune/immune‑mediated with vasculitis as a key pathogenic mechanism. (espinoza2020cogan’ssyndromeclinical pages 1-3, greco2013coganssyndromean pages 2-3)

Immunologic evidence discussed in authoritative reviews includes: - Autoantibodies reported against corneal antigens, inner ear constituents, and endothelial antigens. (Greco 2013; https://doi.org/10.1016/j.autrev.2012.07.012) (greco2013coganssyndromean pages 2-3, greco2013coganssyndromean pages 1-2) - A proposed “Cogan peptide” with homology to CD148 (PTPRJ) and connexin 26 (GJB2), with reports that peptide‑specific antibodies can localize to the cochlea and transfer disease in animal models. (greco2013coganssyndromean pages 2-3)

Infectious/trigger hypotheses (non‑causal, indirect): Reviews discuss potential infection‑trigger models (e.g., viral triggers and molecular mimicry concepts), but evidence remains limited and non‑definitive. (tayershifman2014coganssyndrome—clinicalguidelines pages 1-2, tayershifman2014coganssyndrome—clinicalguidelines pages 2-3)

2.2 Risk factors

Robust population‑level risk factors are not established; epidemiology is rare and incidence is often described as unknown or not measurable due to the small number of cases. (ince2023coganssyndrome pages 1-2, tayershifman2014coganssyndrome—clinicalguidelines pages 1-2)

2.3 Protective factors

No validated protective genetic or environmental factors were identified in the retrieved evidence.

2.4 Gene–environment interactions

No validated gene–environment interaction data were identified in the retrieved evidence.

3. Phenotypes

3.1 Core phenotypic domains

CS phenotypes are commonly grouped as: 1) Ocular inflammatory disease (classically interstitial keratitis; also uveitis, episcleritis/scleritis, retinal vasculitis, etc.) (rucklova2023paediatriccogan´ssyndrome pages 2-4, tayershifman2014coganssyndrome—clinicalguidelines pages 2-3) 2) Audiovestibular disease (vertigo, tinnitus, nausea/vomiting, ataxia, progressive SNHL) (wang2023cogan’ssyndromeis pages 1-2, espinoza2020cogan’ssyndromeclinical pages 1-3) 3) Systemic vasculitis / inflammatory manifestations (fever, arthralgia, anemia, neurologic and gastrointestinal involvement; and aortitis) (wang2023cogan’ssyndromeis pages 1-2, wang2023cogan’ssyndromeis pages 2-5)

3.2 Phenotype characteristics with frequency (where available)

Pediatric case‑based aggregate (n=55; Rücklová 2023): - Ocular findings: 55/55 (100%) - Interstitial keratitis: 34/55 (62%) - Sensorineural hearing deficit: 55/55 (100%) - Vestibular symptoms: 37/54 (69%) - Any systemic symptoms: 32/55 (58%) - Aortitis: 9/55 (16%); 2/55 deaths reported (mortality 3.6%) (published 2023-06; https://doi.org/10.1186/s12969-023-00830-x) (rucklova2023paediatriccogan´ssyndrome pages 2-4)

HPO term suggestions (non‑exhaustive): - Interstitial keratitis — HP:0000496 (suggested) - Uveitis — HP:0000554 (suggested) - Scleritis / episcleritis — HP:0100537 / HP:0200042 (suggested) - Sensorineural hearing loss — HP:0000407 (suggested) - Vertigo — HP:0002321 (suggested) - Tinnitus — HP:0000360 (suggested) - Aortitis — HP:0004948 (suggested) - Fever — HP:0001945 (suggested) - Arthralgia — HP:0002829 (suggested)

3.3 Quality of life (QoL) impact

QoL is primarily affected by permanent or fluctuating hearing loss, vestibular dysfunction, and visual symptoms. A key clinical consequence emphasized in reviews is progression to irreversible bilateral profound SNHL in a substantial fraction of patients, driving cochlear implant candidacy. (shamriz2018autoimmuneinnerear pages 1-2, espinoza2020cogan’ssyndromeclinical pages 4-5)

4. Genetic/Molecular Information

4.1 Causal genes

No monogenic causal gene for CS is established in the retrieved evidence; CS is treated as an immune‑mediated syndrome rather than a Mendelian disorder. (tayershifman2014coganssyndrome—clinicalguidelines pages 1-2, shamriz2018autoimmuneinnerear pages 1-2)

4.2 Candidate autoantigens/biomarkers (not diagnostic)

Key points: No serum autoantibody is sufficiently validated for routine diagnosis. (shamriz2018autoimmuneinnerear pages 1-2)

  • Anti‑HSP70 has been proposed in the context of autoimmune inner ear disease and studied in CS cohorts, with variable positivity across studies and higher positivity reported in typical CS in at least one cohort summarized by Shamriz et al. (2018). (shamriz2018autoimmuneinnerear pages 1-2)
  • “Cogan peptide”/cross‑reactive targets (CD148/PTPRJ; connexin 26/GJB2) and endothelial antigen reactivity have been described in reviews. (greco2013coganssyndromean pages 2-3, tayershifman2014coganssyndrome—clinicalguidelines pages 1-2)
  • Inflammatory markers (ESR/CRP) are commonly elevated during active disease; IL‑6 can be elevated and has been used as rationale for IL‑6 blockade in case reports/series contexts. (wang2023cogan’ssyndromeis pages 1-2, wang2023cogan’ssyndromeis pages 2-5)

CHEBI suggestions (where relevant): - Prednisone (CHEBI term exists) - Methylprednisolone (CHEBI term exists) - Methotrexate (CHEBI term exists) - Cyclophosphamide (CHEBI term exists) - Tocilizumab (biologic; CHEBI mapping may exist depending on ontology version)

4.3 Epigenetics / chromosomal abnormalities

No CS‑specific epigenetic or chromosomal abnormality evidence was identified in the retrieved sources.

5. Environmental Information

No validated environmental toxins, lifestyle factors, or specific infectious agents were established as causal in the retrieved evidence. Reviews discuss infectious trigger hypotheses but without definitive confirmation. (tayershifman2014coganssyndrome—clinicalguidelines pages 1-2, greco2013coganssyndromean pages 1-2)

6. Mechanism / Pathophysiology

6.1 Mechanistic model (causal chain)

Proposed upstream trigger(s): immune activation possibly triggered by infection or other exposures in a susceptible host (hypothesized). (tayershifman2014coganssyndrome—clinicalguidelines pages 1-2)

Core immune process: autoimmune/immune‑mediated inflammation with vasculitic injury affecting eye and inner ear; systemic manifestations arise when larger/variable vessels are involved (including the aorta). (greco2013coganssyndromean pages 2-3, tayershifman2014coganssyndrome—clinicalguidelines pages 2-3)

Downstream tissue injury and clinical manifestations: - Corneal/ocular inflammation → interstitial keratitis/uveitis/scleritis → pain, photophobia, blurred vision. (tayershifman2014coganssyndrome—clinicalguidelines pages 2-3, rucklova2023paediatriccogan´ssyndrome pages 2-4) - Inner ear inflammation/microvascular injury → cochleovestibular dysfunction → vertigo/tinnitus and progressive SNHL → potential irreversible deafness. (wang2023cogan’ssyndromeis pages 1-2, shamriz2018autoimmuneinnerear pages 1-2) - Large vessel vasculitis (aortitis) → aortic root/valvular dysfunction and vascular complications (aneurysm/stenosis) → morbidity/mortality risk. (wang2023cogan’ssyndromeis pages 1-2, espinoza2020cogan’ssyndromeclinical pages 4-5, tayershifman2014coganssyndrome—clinicalguidelines pages 2-3)

6.2 Pathways and cellular processes (ontology suggestions)

GO Biological Process (suggested): - GO:0006954 inflammatory response - GO:0002682 regulation of immune system process - GO:0006955 immune response - GO:0002526 acute inflammatory response - GO:0006952 defense response - GO:0050729 positive regulation of inflammatory response

CL Cell types (suggested, consistent with inflammatory vasculitis): - Macrophage — CL:0000235 - T cell — CL:0000084 - B cell / plasma cell — CL:0000236 / CL:0000786 - Vascular endothelial cell — CL:0000115

6.3 Molecular profiling (transcriptomics/proteomics/metabolomics)

No validated CS‑specific multi‑omics signatures were identified in the retrieved evidence.

7. Anatomical Structures Affected

7.1 Organ/system level (primary)

  • Eye (cornea; uvea; sclera) (tayershifman2014coganssyndrome—clinicalguidelines pages 2-3, rucklova2023paediatriccogan´ssyndrome pages 2-4)
  • Inner ear (cochlea; vestibular apparatus) (shamriz2018autoimmuneinnerear pages 1-2, rucklova2023paediatriccogan´ssyndrome pages 2-4)
  • Large vessels, especially aorta (aortitis/aortic root involvement) (wang2023cogan’ssyndromeis pages 1-2, tayershifman2014coganssyndrome—clinicalguidelines pages 2-3)

UBERON suggestions: - Eye — UBERON:0000970 - Cornea — UBERON:0000964 - Inner ear — UBERON:0001845 - Cochlea — UBERON:0001846 - Aorta — UBERON:0000947

7.2 Tissue/cell level

Evidence supports inflammatory infiltration and vasculitic pathology in relevant tissues in some reports and reviews, consistent with immune‑mediated injury; definitive cell‑resolved mapping is not standardized. (greco2013coganssyndromean pages 4-4)

7.3 Subcellular level

No CS‑specific subcellular compartment pathology was identified.

8. Temporal Development

8.1 Onset and course

  • Often described in young adults (20s–30s) but can occur in children and older adults. (wang2023cogan’ssyndromeis pages 1-2, shamriz2018autoimmuneinnerear pages 1-2)
  • Course may be relapsing and evolve over years; early treatment is emphasized to limit irreversible hearing loss. (espinoza2020cogan’ssyndromeclinical pages 4-5)

Pediatric timing: pediatric literature review reports median age 12 years (range 3–18). (rucklova2023paediatriccogan´ssyndrome pages 2-4)

8.2 Typical vs atypical timing

  • The “2‑year” separation is used to operationalize typical vs atypical disease, but some expert commentary suggests the distinction may be less important for long‑term management than prevention of disability and systemic complications. (espinoza2020cogan’ssyndromeclinical pages 4-5)

9. Inheritance and Population

9.1 Epidemiology

Population prevalence/incidence is not well defined in the retrieved sources.

Case‑count estimates and age/sex: - Reviews describe ~250 reported cases (2018 review) and “few hundred” cases since 1945. (shamriz2018autoimmuneinnerear pages 1-2, wang2023cogan’ssyndromeis pages 2-5) - One cohort summarized in Shamriz 2018: median onset 25 years (range 5–63) and no clear gender predominance. (shamriz2018autoimmuneinnerear pages 1-2) - Pediatric aggregation: male 31/54 (57%). (rucklova2023paediatriccogan´ssyndrome pages 2-4)

9.2 Inheritance

No Mendelian inheritance pattern is established; CS is treated as non‑Mendelian/immune‑mediated. (tayershifman2014coganssyndrome—clinicalguidelines pages 1-2, shamriz2018autoimmuneinnerear pages 1-2)

10. Diagnostics

10.1 Clinical criteria and diagnostic approach

Across reviews, CS diagnosis is clinical, requiring: 1) inflammatory ocular disease, 2) audiovestibular involvement (often rapidly progressing SNHL), and 3) exclusion of alternative causes, especially syphilis and other infectious/autoimmune mimics. (tayershifman2014coganssyndrome—clinicalguidelines pages 2-3, rucklova2023paediatriccogan´ssyndrome pages 2-4)

Direct quote (review text): “To date, since there is no specific test, the diagnosis of CS is based on clinical findings…” (Tayer‑Shifman 2014, published 2014-01; https://doi.org/10.1007/s12016-013-8406-7) (tayershifman2014coganssyndrome—clinicalguidelines pages 2-3)

10.2 Laboratory tests and biomarkers

  • Inflammatory markers (ESR/CRP) are non‑specific but used to track disease activity. (wang2023cogan’ssyndromeis pages 1-2, rucklova2023paediatriccogan´ssyndrome pages 2-4)
  • No single serum autoantibody is accepted for routine diagnostic workup. (shamriz2018autoimmuneinnerear pages 1-2)
  • Workup frequently includes broad autoimmune serologies (ANA/ANCA/RF etc.) primarily to evaluate alternative diagnoses; positivity in larger CS studies is generally low per reviews. (shamriz2018autoimmuneinnerear pages 1-2, marrerogonzalez2025audiovestibularoutcomesin pages 2-4)

10.3 Imaging and functional testing

  • Audiometry (pure tone audiogram) for quantification and follow‑up of SNHL. (tayershifman2014coganssyndrome—clinicalguidelines pages 2-3)
  • CT/MRI head/inner ear to exclude other causes; MRI may show labyrinthitis or other inner ear changes though can be normal. (espinoza2020cogan’ssyndromeclinical pages 1-3, marrerogonzalez2025audiovestibularoutcomesin pages 2-4)
  • Echocardiography is emphasized for aortitis/aortic valvular dysfunction assessment once CS suspected/diagnosed. (tayershifman2014coganssyndrome—clinicalguidelines pages 2-3, wang2023cogan’ssyndromeis pages 2-5)
  • FDG‑PET/CT has been used/recommended in selected cases to detect aortitis or inflammatory activity (investigational/adjunct). (espinoza2020cogan’ssyndromeclinical pages 4-5, tayershifman2014coganssyndrome—clinicalguidelines pages 2-3)

10.4 Differential diagnosis (examples from pediatric diagnostic table)

Important exclusions include syphilis, tuberculosis, chlamydia, sarcoidosis, PAN, ANCA‑associated vasculitides, Behçet disease, Takayasu arteritis, Vogt‑Koyanagi‑Harada syndrome, Susac syndrome, and connective tissue disorders. (rucklova2023paediatriccogan´ssyndrome pages 2-4)

10.5 Genetic testing

Genetic testing is not a standard diagnostic tool for CS based on the retrieved evidence (no established causal gene). (tayershifman2014coganssyndrome—clinicalguidelines pages 1-2)

11. Outcome / Prognosis

11.1 Hearing and visual outcomes

  • Hearing loss may progress to irreversible bilateral profound SNHL in approximately half of patients in at least one review. (shamriz2018autoimmuneinnerear pages 1-2)
  • A 2023 literature review states “Nearly 43% develop deafness” and “blindness has been reported in 8%.” (Wang 2023, published 2023-05; https://doi.org/10.1186/s12886-023-02966-6) (wang2023cogan’ssyndromeis pages 1-2)

11.2 Systemic vasculitis complications

Systemic involvement is common in some series/reviews (often cited up to ~80%), with aortitis around ~10% in multiple reviews and higher rates in pediatric aggregation. (espinoza2020cogan’ssyndromeclinical pages 1-3, tayershifman2014coganssyndrome—clinicalguidelines pages 2-3, rucklova2023paediatriccogan´ssyndrome pages 2-4)

12. Treatment

12.1 Pharmacotherapy (current standard and escalation)

First‑line: high‑dose systemic corticosteroids for acute/active disease, with topical ocular steroids for mild ocular disease. (espinoza2020cogan’ssyndromeclinical pages 4-5, tayershifman2014coganssyndrome—clinicalguidelines pages 2-3)

Timing matters for hearing: high‑dose steroids given within ~2 weeks of auditory symptom onset improve odds of hearing recovery. (espinoza2020cogan’ssyndromeclinical pages 4-5)

Steroid‑sparing csDMARDs (examples): methotrexate, azathioprine, cyclosporine, mycophenolate mofetil; cyclophosphamide for severe systemic vasculitis. (mendes2026atypicalcogan’ssyndrome pages 2-3, tayershifman2014coganssyndrome—clinicalguidelines pages 2-3, marrerogonzalez2025audiovestibularoutcomesin pages 2-4)

Biologics (refractory disease): anti‑TNF agents are most frequently emphasized; infliximab is highlighted as a leading option in multiple reviews. (espinoza2020cogan’ssyndromeclinical pages 4-5, tayershifman2014coganssyndrome—clinicalguidelines pages 1-2)

Quantitative outcomes from treatment literature (selected): - Infliximab: 80% response rate at 6 months for vestibuloauditory symptoms in a treatment review summary. (Espinoza 2020, published 2020-06; https://doi.org/10.1007/s11882-020-00945-1) (espinoza2020cogan’ssyndromeclinical pages 4-5) - Adult systematic review of case reports (n=79): 60% treated only with oral steroids had no audiologic improvement, while 85.7% treated with biologic DMARDs improved audiologically. (Marrero‑Gonzalez 2025; https://doi.org/10.1007/s00405-024-08878-5) (marrerogonzalez2025audiovestibularoutcomesin pages 1-2)

Newer/experimental approaches noted in recent reports: - IL‑6 blockade (tocilizumab) used in refractory cases; elevated IL‑6 reported in some cases and normalization of inflammatory markers after tocilizumab reported in case‑based narratives. (wang2023cogan’ssyndromeis pages 2-5) - JAK inhibitors (e.g., tofacitinib) used in selected refractory cases for systemic/joint manifestations (hearing stabilization variable). (wang2023cogan’ssyndromeis pages 1-2)

12.2 Surgical and interventional

Cochlear implantation (CI): - CI is recommended early in profound SNHL because inflammatory inner ear disease can cause intracochlear fibrosis/neo‑ossification, complicating later implantation. (shamriz2018autoimmuneinnerear pages 1-2) - Pediatric case‑based report describes evaluation for unilateral CI after one ear remained deaf despite immunomodulatory therapy; MRI resolution of inflammation raised concern for intracochlear fibrosis, “emphasiz[ing] the urgency of CI.” (rucklova2023paediatriccogan´ssyndrome pages 2-4)

12.3 MAXO term suggestions (selected)

  • Systemic glucocorticoid therapy — MAXO term exists (suggested)
  • Immunosuppressive therapy — MAXO term exists (suggested)
  • Tumor necrosis factor inhibitor therapy — MAXO term exists (suggested)
  • Cochlear implantation — MAXO term exists (suggested)
  • Echocardiography (for surveillance) — MAXO term exists (suggested)

12.4 Clinical trials

No CS‑specific interventional trials were identified in the retrieved ClinicalTrials.gov search results; current evidence base is dominated by observational data, case series, and case reports. (Evidence state: no relevant clinical trials retrieved)

13. Prevention

No established primary prevention strategy exists. Practical prevention is largely tertiary prevention: early recognition and immunosuppression to prevent irreversible SNHL and monitoring for aortitis/vascular complications. (espinoza2020cogan’ssyndromeclinical pages 4-5, tayershifman2014coganssyndrome—clinicalguidelines pages 2-3)

14. Other Species / Natural Disease

No naturally occurring CS equivalent in non‑human species was identified in the retrieved evidence.

15. Model Organisms

No standardized model organism resource or widely used experimental model for CS was identified in the retrieved evidence; however, immune reactivity to candidate antigens (“Cogan peptide”) and disease transfer/induction has been discussed in reviews, implying experimental work exists but is not established as a canonical model system. (greco2013coganssyndromean pages 2-3)

Key quantitative/clinical facts table

Data point Value Population/Study Year Source (first author) DOI/URL Citation context IDs
Typical Cogan syndrome definition Ocular and audiovestibular symptoms occur within 2 years; classically non-syphilitic interstitial keratitis plus Ménière-like audiovestibular disease Clinical definition/review 2023 Wang https://doi.org/10.1186/s12886-023-02966-6 (wang2023cogan’ssyndromeis pages 1-2, espinoza2020cogan’ssyndromeclinical pages 1-3)
Atypical Cogan syndrome definition Delay >2 years between ocular and audiovestibular manifestations and/or non-interstitial-keratitis ocular inflammation; systemic manifestations more frequent Clinical definition/review 2026 Mendes https://doi.org/10.1159/000551227 (mendes2026atypicalcogan’ssyndrome pages 2-2, mendes2026atypicalcogan’ssyndrome pages 2-3)
Interstitial keratitis frequency 34/55 (62%) Pediatric literature review cohort, n=55 2023 Rücklová https://doi.org/10.1186/s12969-023-00830-x (rucklova2023paediatriccogan´ssyndrome pages 2-4)
Vestibular symptoms frequency 37/54 (69%) Pediatric literature review cohort, n=55 2023 Rücklová https://doi.org/10.1186/s12969-023-00830-x (rucklova2023paediatriccogan´ssyndrome pages 2-4)
Any systemic symptoms 32/55 (58%) Pediatric literature review cohort, n=55 2023 Rücklová https://doi.org/10.1186/s12969-023-00830-x (rucklova2023paediatriccogan´ssyndrome pages 2-4)
Aortitis frequency 9/55 (16%) Pediatric literature review cohort, n=55 2023 Rücklová https://doi.org/10.1186/s12969-023-00830-x (rucklova2023paediatriccogan´ssyndrome pages 2-4)
Mortality 2/55 (3.6%) Pediatric literature review cohort, n=55 2023 Rücklová https://doi.org/10.1186/s12969-023-00830-x (rucklova2023paediatriccogan´ssyndrome pages 2-4)
Biologic DMARD audiologic improvement 12/14 (85.7%) improved Adult systematic review/case reports, n=79 total 2025 Marrero-Gonzalez https://doi.org/10.1007/s00405-024-08878-5 (marrerogonzalez2025audiovestibularoutcomesin pages 1-2, marrerogonzalez2025audiovestibularoutcomesin pages 2-4)
Oral steroids only: no audiologic improvement 18/30 (60.0%) had no improvement Adult systematic review/case reports, n=79 total 2025 Marrero-Gonzalez https://doi.org/10.1007/s00405-024-08878-5 (marrerogonzalez2025audiovestibularoutcomesin pages 1-2)
Vestibular symptoms in steroid-resistant vs steroid-responsive patients 79.5% vs 57.9% Adult systematic review/case reports, n=79 total 2025 Marrero-Gonzalez https://doi.org/10.1007/s00405-024-08878-5 (marrerogonzalez2025audiovestibularoutcomesin pages 1-2)
Deafness frequency ~43% develop deafness Clinical review/literature review 2023 Wang https://doi.org/10.1186/s12886-023-02966-6 (wang2023cogan’ssyndromeis pages 1-2)
Blindness frequency 8% Clinical review/literature review 2023 Wang https://doi.org/10.1186/s12886-023-02966-6 (wang2023cogan’ssyndromeis pages 1-2)
Infliximab vestibuloauditory response 80% response at 6 months Review of treatment evidence 2020 Espinoza https://doi.org/10.1007/s11882-020-00945-1 (espinoza2020cogan’ssyndromeclinical pages 4-5)
Ocular response to steroids 84% French series/review summarized in treatment review 2020 Espinoza https://doi.org/10.1007/s11882-020-00945-1 (espinoza2020cogan’ssyndromeclinical pages 4-5)
Ocular response to DMARDs 90% French series/review summarized in treatment review 2020 Espinoza https://doi.org/10.1007/s11882-020-00945-1 (espinoza2020cogan’ssyndromeclinical pages 4-5)
Ocular response to biologics 100% French series/review summarized in treatment review 2020 Espinoza https://doi.org/10.1007/s11882-020-00945-1 (espinoza2020cogan’ssyndromeclinical pages 4-5)
Hearing progression to irreversible bilateral profound SNHL Approximately half of patients Immunology review 2018 Shamriz https://doi.org/10.1155/2018/1498640 (shamriz2018autoimmuneinnerear pages 1-2)

Table: This table compiles the most actionable quantitative and definitional findings for Cogan syndrome from the retrieved evidence. It highlights diagnostic distinctions, pediatric and adult cohort statistics, and treatment/outcome figures useful for rapid knowledge-base entry.

Expert opinion / authoritative analysis (synthesis)

1) Diagnosis remains syndromic and exclusionary: multiple authoritative reviews emphasize there is no specific diagnostic test, and evaluation must exclude infections (syphilis, TB) and systemic inflammatory mimics while assessing for vasculitis (including echocardiographic screening for aortitis). (tayershifman2014coganssyndrome—clinicalguidelines pages 2-3, rucklova2023paediatriccogan´ssyndrome pages 2-4) 2) Early immunosuppression is time‑critical for hearing: steroid treatment in the first ~2 weeks of auditory symptom onset is repeatedly highlighted as improving hearing recovery odds, but many patients still progress to profound SNHL. (espinoza2020cogan’ssyndromeclinical pages 4-5, shamriz2018autoimmuneinnerear pages 1-2) 3) Biologic therapy is increasingly used in refractory disease: anti‑TNF therapy (especially infliximab) is the most consistently emphasized biologic across reviews, with aggregated evidence suggesting improved vestibuloauditory outcomes compared with steroids alone in case‑based evidence. (espinoza2020cogan’ssyndromeclinical pages 4-5, marrerogonzalez2025audiovestibularoutcomesin pages 1-2)

Limitations of this report

  • Authoritative disease identifier mappings (MONDO/Orphanet/ICD/MeSH) were not retrievable from the provided evidence set, so identifiers are not asserted.
  • Many “latest developments” in 2023–2024 are case‑based; high‑quality randomized trials remain scarce or absent in the retrieved evidence, limiting certainty for comparative efficacy claims.

References

  1. (wang2023cogan’ssyndromeis pages 1-2): Yanqing Wang, Shichao Tang, Chong Shao, and Yu Liu. Cogan’s syndrome is more than just keratitis: a case-based literature review. BMC Ophthalmology, May 2023. URL: https://doi.org/10.1186/s12886-023-02966-6, doi:10.1186/s12886-023-02966-6. This article has 12 citations and is from a peer-reviewed journal.

  2. (espinoza2020cogan’ssyndromeclinical pages 1-3): Gabriela Mabel Espinoza, Joseph Wheeler, Katherine K. Temprano, and Angela Prost Keller. Cogan’s syndrome: clinical presentations and update on treatment. Current Allergy and Asthma Reports, 20:1-6, Jun 2020. URL: https://doi.org/10.1007/s11882-020-00945-1, doi:10.1007/s11882-020-00945-1. This article has 69 citations and is from a peer-reviewed journal.

  3. (tayershifman2014coganssyndrome—clinicalguidelines pages 2-3): Oshrat E. Tayer-Shifman, Ophir Ilan, Hodaya Tovi, and Yuval Tal. Cogan's syndrome—clinical guidelines and novel therapeutic approaches. Clinical Reviews in Allergy & Immunology, 47:65-72, Jan 2014. URL: https://doi.org/10.1007/s12016-013-8406-7, doi:10.1007/s12016-013-8406-7. This article has 73 citations and is from a peer-reviewed journal.

  4. (espinoza2020cogan’ssyndromeclinical pages 4-5): Gabriela Mabel Espinoza, Joseph Wheeler, Katherine K. Temprano, and Angela Prost Keller. Cogan’s syndrome: clinical presentations and update on treatment. Current Allergy and Asthma Reports, 20:1-6, Jun 2020. URL: https://doi.org/10.1007/s11882-020-00945-1, doi:10.1007/s11882-020-00945-1. This article has 69 citations and is from a peer-reviewed journal.

  5. (shamriz2018autoimmuneinnerear pages 1-2): Oded Shamriz, Yuval Tal, and Menachem Gross. Autoimmune inner ear disease: immune biomarkers, audiovestibular aspects, and therapeutic modalities of cogan's syndrome. Journal of Immunology Research, 2018:1-8, Apr 2018. URL: https://doi.org/10.1155/2018/1498640, doi:10.1155/2018/1498640. This article has 52 citations and is from a peer-reviewed journal.

  6. (rucklova2023paediatriccogan´ssyndrome pages 2-4): Kristina Rücklová, Thekla von Kalle, Assen Koitschev, Katrin Gekeler, Miriam Scheltdorf, Anita Heinkele, Friederike Blankenburg, Ina Kötter, and Anton Hospach. Paediatric cogan´s syndrome - review of literature, case report and practical approach to diagnosis and management. Pediatric Rheumatology Online Journal, Jun 2023. URL: https://doi.org/10.1186/s12969-023-00830-x, doi:10.1186/s12969-023-00830-x. This article has 7 citations.

  7. (ince2023coganssyndrome pages 1-2): B İnce and S Kamalı. Cogan's syndrome. Unknown journal, 2023.

  8. (mendes2026atypicalcogan’ssyndrome pages 2-2): João Mendes, Francisco Mendes, Diogo Valente Fortunato, João Vasco Garrido, Rita Condesso, and Augusto Candeias. Atypical cogan’s syndrome presenting as anterior scleritis: case report. Case Reports in Ophthalmology, 17:371-379, Mar 2026. URL: https://doi.org/10.1159/000551227, doi:10.1159/000551227. This article has 0 citations and is from a peer-reviewed journal.

  9. (mendes2026atypicalcogan’ssyndrome pages 2-3): João Mendes, Francisco Mendes, Diogo Valente Fortunato, João Vasco Garrido, Rita Condesso, and Augusto Candeias. Atypical cogan’s syndrome presenting as anterior scleritis: case report. Case Reports in Ophthalmology, 17:371-379, Mar 2026. URL: https://doi.org/10.1159/000551227, doi:10.1159/000551227. This article has 0 citations and is from a peer-reviewed journal.

  10. (marrerogonzalez2025audiovestibularoutcomesin pages 1-2): Alejandro R. Marrero-Gonzalez, Celine Ward, Shaun A. Nguyen, Seth S. Jeong, and Habib G. Rizk. Audiovestibular outcomes in adult patients with cogan syndrome: a systematic review. European Archives of Oto-Rhino-Laryngology, 282:23-35, Aug 2025. URL: https://doi.org/10.1007/s00405-024-08878-5, doi:10.1007/s00405-024-08878-5. This article has 6 citations and is from a peer-reviewed journal.

  11. (greco2013coganssyndromean pages 2-3): A. Greco, A. Gallo, M. Fusconi, G. Magliulo, R. Turchetta, C. Marinelli, G.F. Macri, A. De Virgilio, and M. de Vincentiis. Cogan's syndrome: an autoimmune inner ear disease. Autoimmunity reviews, 12 3:396-400, Jan 2013. URL: https://doi.org/10.1016/j.autrev.2012.07.012, doi:10.1016/j.autrev.2012.07.012. This article has 160 citations and is from a peer-reviewed journal.

  12. (greco2013coganssyndromean pages 1-2): A. Greco, A. Gallo, M. Fusconi, G. Magliulo, R. Turchetta, C. Marinelli, G.F. Macri, A. De Virgilio, and M. de Vincentiis. Cogan's syndrome: an autoimmune inner ear disease. Autoimmunity reviews, 12 3:396-400, Jan 2013. URL: https://doi.org/10.1016/j.autrev.2012.07.012, doi:10.1016/j.autrev.2012.07.012. This article has 160 citations and is from a peer-reviewed journal.

  13. (tayershifman2014coganssyndrome—clinicalguidelines pages 1-2): Oshrat E. Tayer-Shifman, Ophir Ilan, Hodaya Tovi, and Yuval Tal. Cogan's syndrome—clinical guidelines and novel therapeutic approaches. Clinical Reviews in Allergy & Immunology, 47:65-72, Jan 2014. URL: https://doi.org/10.1007/s12016-013-8406-7, doi:10.1007/s12016-013-8406-7. This article has 73 citations and is from a peer-reviewed journal.

  14. (wang2023cogan’ssyndromeis pages 2-5): Yanqing Wang, Shichao Tang, Chong Shao, and Yu Liu. Cogan’s syndrome is more than just keratitis: a case-based literature review. BMC Ophthalmology, May 2023. URL: https://doi.org/10.1186/s12886-023-02966-6, doi:10.1186/s12886-023-02966-6. This article has 12 citations and is from a peer-reviewed journal.

  15. (greco2013coganssyndromean pages 4-4): A. Greco, A. Gallo, M. Fusconi, G. Magliulo, R. Turchetta, C. Marinelli, G.F. Macri, A. De Virgilio, and M. de Vincentiis. Cogan's syndrome: an autoimmune inner ear disease. Autoimmunity reviews, 12 3:396-400, Jan 2013. URL: https://doi.org/10.1016/j.autrev.2012.07.012, doi:10.1016/j.autrev.2012.07.012. This article has 160 citations and is from a peer-reviewed journal.

  16. (marrerogonzalez2025audiovestibularoutcomesin pages 2-4): Alejandro R. Marrero-Gonzalez, Celine Ward, Shaun A. Nguyen, Seth S. Jeong, and Habib G. Rizk. Audiovestibular outcomes in adult patients with cogan syndrome: a systematic review. European Archives of Oto-Rhino-Laryngology, 282:23-35, Aug 2025. URL: https://doi.org/10.1007/s00405-024-08878-5, doi:10.1007/s00405-024-08878-5. This article has 6 citations and is from a peer-reviewed journal.