Febrile Infection-Related Epilepsy Syndrome

1. Disease Information

FIRES is a rare, catastrophic epileptic encephalopathy in which a previously healthy person — usually a school-age child — develops explosive, drug-resistant status epilepticus a few days after a banal, self-limited febrile illness (a cold, a stomach bug). The fever itself is gone or fading by the time the brain catches fire. There's no tumor, no stroke, no obvious infection in the brain, no metabolic crash to explain it. The seizures just won't stop, often for weeks to months, and survivors are almost always left with lasting epilepsy and cognitive damage.

The clean way to think about the naming, settled by the 2018 international consensus (Hirsch et al., Epilepsia 2018;59:739–744, doi:10.1111/epi.14016, verify PMID):

• NORSE (New-Onset Refractory Status Epilepticus) is the umbrella — a clinical presentation, not a diagnosis: refractory SE with no readily identifiable acute structural, toxic, or metabolic cause, in someone without active epilepsy or a relevant prior neurological disorder.
• FIRES is the subtype of NORSE that requires a preceding febrile infection, with fever starting between 2 weeks and 24 hours before the refractory SE onset. Fever need not be present at SE onset. FIRES applies to any age (the consensus deliberately removed the old pediatric-only restriction).
• Cryptogenic NORSE/FIRES = the ~50% where no cause is found even after full workup. Most FIRES ends up here.

Quote (consensus framing, per NORSE Institute summary of Hirsch 2018): "FIRES is a subtype of NORSE that involves a prior febrile infection, with fever starting between 2 weeks and 24 hours prior to the onset of refractory status epilepticus."

Key identifiers:

Common synonyms / historical names (worth carrying as synonyms, because the older names encode obsolete assumptions): - Fever-Induced Refractory Epileptic Encephalopathy in School-age children (FIRES — the original Nabbout acronym) - Acute Encephalitis with Refractory Repetitive Partial Seizures (AERRPS, Japanese literature) - Devastating Epileptic Encephalopathy in School-age Children (DESC) - Idiopathic catastrophic epileptic encephalopathy; "new-onset cryptogenic febrile SE"

Data provenance: almost entirely disease-level aggregated from case reports and small case series — there is no large individual-patient EHR registry, and worldwide only ~on the order of 100+ well-characterized cases have been published. This scarcity is itself a load-bearing fact for every "frequency" and "prevalence" claim below.

Sources: Orphanet 163703, NORD, Hirsch 2018 consensus, Lit review PMC9756623.

2. Etiology

Causal factors — the honest answer is "unknown trigger, stereotyped response." The leading model is that a nonspecific febrile infection acts as a trigger, not a cause, unmasking a runaway innate-immune / autoinflammatory cascade in the brain. Think of the fever as the match and a primed neuroinflammatory system as the dry grass — the fire's character comes from the grass, not the match. Most likely, per Orphanet, "FIRES is an immune-inflammatory-mediated epileptic encephalopathy, with a vicious circle of inflammation and hyperexcitability."

• Infectious triggers: many pathogens have been reported preceding FIRES (influenza, HHV-6, enteroviruses, Mycoplasma, respiratory/GI viruses), but no single organism is consistently found, and virus is generally not recoverable from CSF/brain — arguing against direct viral encephalitis and for a para-/post-infectious immune mechanism.
• Not classic autoimmune encephalitis: neuronal autoantibodies (anti-NMDAR, etc.) are usually absent in cryptogenic FIRES; this distinguishes it from antibody-mediated NORSE, which is a separate branch of the NORSE tree.

Genetic risk factors: No causal Mendelian gene. The candidate-gene study by Appenzeller et al. (2012, Dev Med Child Neurol; PMID:23066759) explicitly showed "FIRES is not caused by SCN1A, POLG, PCDH19 mutations or rare copy number variations." What does recur is susceptibility in innate-immune / cytokine genes: - IL1RN (IL-1 receptor antagonist gene) — a VNTR allele and a risk haplotype were over-represented in FIRES patients vs controls; the index anakinra-responder carried multiple IL1RN variants with reduced intracellular IL-1RA expression (Clarkson et al. 2019, Ann Neurol; PMID:30779222). - Emerging single reports of rare de novo variants in innate-immune/microglial genes — e.g., a de novo pathogenic CSF1R variant implicating microglial dysfunction (Fisher et al. 2025, Epilepsia, doi:10.1111/epi.18538, verify PMID). These are individual leads, not established causes.

Environmental / demographic risk factors: young school age (peak ~7–10 yr), possibly slight male predominance, and simply having a recent febrile infection. No occupational/toxic exposures implicated.

Protective factors: none established genetically or environmentally. Suggestively, the IL1RN findings imply that adequate endogenous IL-1RA function is protective and its functional deficiency is permissive — an inverted-protection framing rather than a discovered protective allele.

Gene–environment interaction is arguably the core of FIRES: a permissive innate-immune genotype (e.g., low-functioning IL-1RA) + a common febrile infection → uncontrolled IL-1β-driven neuroinflammation. This G×E convergence is the single most curation-worthy mechanistic claim.

Sources: Appenzeller 2012 PMID:23066759, Clarkson 2019 PMID:30779222, "Fighting autoinflammation in FIRES" PMID:35356746, Fisher 2025 CSF1R.

3. Phenotypes

Clinical course runs in three phases (per lit review PMC9756623):

Prodromal phase — mild febrile illness (URI or GI), 1–2 days, then a symptom-free interval of 24 h–2 weeks.

Acute phase — the defining catastrophe: - Status epilepticus, refractory / super-refractory — HP:0002133 (Status epilepticus), with focal seizures with impaired awareness (HP:0002384) evolving to bilateral tonic-clonic seizures (HP:0002069); often multifocal with migrating perisylvian/fronto-temporal foci. Frequency: ~100% (defining feature). - Seizures broadly — HP:0001250. Frequency: obligate. - Encephalopathy / impaired consciousness — HP:0002383 (Focal-onset) / HP:0001259 (Coma) during barbiturate suppression. Frequency: very frequent. - Fever preceding — HP:0001945. Frequency: obligate by definition (in the preceding window). - Dysautonomia (tachycardia, blood pressure lability) during ICU course — HP:0011448 (Abnormal autonomic nervous system physiology). Occasional.

Chronic phase — near-universal in survivors: - Refractory/pharmacoresistant epilepsy — HP:0011171 (Refractory status is upstream) / HP:0002197 is not right; use HP:0001250 + intractability noted; Drug-resistant epilepsy maps well to HP:0011097 (Epileptic encephalopathy) as the overarching descriptor. Per PMC9756623: "among 66 of the 68 survived, 63 of them continued to have epilepsy refractory to any type of treatment." Frequency: ~90–95% of survivors. - Intellectual disability — HP:0001249. Roughly one-third normal/borderline, one-third mild–moderate ID, one-third severe ID/vegetative. Frequency: ~66–100% of survivors. - Cognitive/memory impairment — HP:0100543 (Cognitive impairment), esp. memory impairment HP:0002354 (mesial temporal injury). Very frequent. - Language impairment / regression — HP:0002463; speech regression HP:0001344. Frequent. - Behavioral / neuropsychiatric changes — HP:0000708 (Behavioral abnormality), including autistic features, ADHD-like symptoms, mood/psychiatric sequelae. Frequent. - Motor deficits — HP:0001324 (Muscle weakness) / HP:0002071 (Abnormality of extrapyramidal motor function); spasticity/ataxia in severe cases. Variable.

Laboratory phenotype: - CSF pleocytosis — mild lymphocytic, in >50% of patients (HP:0012229, Abnormal CSF protein/cellular content). - Elevated CSF & serum pro-inflammatory cytokines/chemokines (IL-6, IL-1β, IL-1RA, IL-8, CXCL/CCL chemokines) — the biochemical signature. - Usually normal glucose, negative viral PCR/cultures, negative or nonspecific autoantibodies.

Onset/severity/progression: onset acute/explosive, pediatric predominant (but any age per consensus); severity severe essentially by definition; acute phase episodic-to-continuous SE lasting weeks–months, then a chronic, often progressive-then-static deficit. QoL impact is profound — survivors frequently need lifelong care, special education, and have high caregiver burden; no FIRES-specific validated QoL instrument exists (generic pediatric epilepsy/QOLCE tools apply).

Sources: PMC9756623, Orphanet.

4. Genetic / Molecular Information

This section is where the template's gene-centric framing mostly does not apply, and that absence is itself the finding.

• Causal genes: none established. FIRES is not Mendelian; there is no OMIM number. Prime epilepsy candidates were formally excluded (SCN1A, POLG, PCDH19, CNVs; Appenzeller 2012, PMID:23066759).
• Susceptibility / modifier loci:
• IL1RN (IL-1 receptor antagonist; HGNC gene IL1RN) — risk VNTR allele + haplotype; functional deficiency of endogenous IL-1RA demonstrated. This is the strongest molecular lead. "FIRES is associated with reduced expression of intracellular IL1RA isoforms and a functional deficiency in IL1RA inhibitory activity" (Clarkson 2019, PMID:30779222).
• Polymorphisms in other cytokine genes reported (small studies) — collectively point to genetically-tuned innate-immune reactivity, not a single locus.
• CSF1R de novo variant — a 2025 single-case lead implicating microglia (Fisher 2025).
• Variant classification / allele frequency / somatic vs germline: Not applicable in the ACMG/ClinVar sense — there is no recurrent pathogenic variant to classify. The IL1RN signals are germline common-variant susceptibility, characterized by association, not pathogenicity calls. gnomAD/ClinVar have no FIRES-defining variant.
• Epigenetics / chromosomal abnormalities: none characterized; karyotype/CMA are normal (part of the diagnostic exclusion).
• Functional consequence framing: the operative molecular defect is a functional loss of anti-inflammatory braking (IL-1RA) rather than a coding change in a neuronal channel — a "loss of the brakes," not a "stuck accelerator."

Ontology handles: gene IL1RN; process GO:0032611 (interleukin-1 beta production), GO:0004908 (interleukin-1 receptor activity), GO:0070498 (interleukin-1-mediated signaling pathway).

Sources: Clarkson 2019 PMID:30779222, Appenzeller 2012 PMID:23066759.

5. Environmental Information

• Infectious agents (trigger): a preceding nonspecific febrile infection is obligatory — but no consistent pathogen. Reported antecedents include respiratory and GI viral illnesses, influenza, HHV-6/HHV-7, enterovirus, adenovirus, Mycoplasma pneumoniae. Crucially, the CNS is usually culture/PCR-negative, so these are triggers of an immune response, not brain-invasive pathogens (NCBI Taxonomy is applicable only as "reported antecedent," not causal agent).
• Toxic / occupational / pollution factors: none implicated (and toxic causes are an exclusion criterion for NORSE/FIRES).
• Lifestyle factors: not applicable — this strikes previously healthy children with no lifestyle contribution.

The environmental story is thin by design: FIRES is defined partly by the absence of a clear structural/toxic/metabolic cause.

6. Mechanism / Pathophysiology

This is the heart of the entry and where the causal chain lives. Best current model — a self-amplifying innate-immune ↔ hyperexcitability loop:

Causal chain (upstream → downstream):

1. Febrile infection primes the innate immune system → systemic + CNS cytokine surge. (trigger)
2. Failure of anti-inflammatory braking — functionally deficient IL-1 receptor antagonist (IL-1RA) cannot restrain IL-1β signaling (Clarkson 2019). This is the pivotal node.
3. Microglial and astrocyte activation (GO:0001774 microglial cell activation; GO:0048143 astrocyte activation) → local release of IL-1β, IL-6, TNF, IL-8, and chemokines (GO:0032635 IL-6 production; GO:0032611 IL-1β production).
4. IL-1β → IL-1R1 signaling on neurons enhances excitability: potentiates NMDA-receptor currents (via Src-family kinase phosphorylation of GluN2B) and suppresses GABAergic inhibition → shifts the excitation/inhibition balance toward excitation (GO:0051968 positive regulation of synaptic transmission, glutamatergic).
5. Blood–brain barrier breakdown — IL-6/IL-1 increase BBB permeability, letting peripheral immune cells and mediators in, further stoking inflammation (a positive-feedback door propped open).
6. Seizures themselves drive more inflammation — seizure activity upregulates cytokines → the "vicious circle of inflammation and hyperexcitability" (Orphanet) → super-refractory status epilepticus.
7. Downstream tissue injury — excitotoxic + inflammatory neuronal death, especially in hippocampus / mesial temporal structures and neocortex → chronic mesial temporal sclerosis, atrophy, and the permanent epilepsy + cognitive phenotype.

Supporting quotes: - "Elevated IL-6 levels in the central nervous system worsen neuroinflammation by activating microglia and astrocytes, releasing pro-inflammatory cytokines, and weakening the blood-brain barrier." - "FIRES is associated with reduced expression of intracellular IL1RA isoforms and a functional deficiency in IL1RA inhibitory activity" (Clarkson 2019, PMID:30779222).

Cell types (CL): microglial cell CL:0000129; astrocyte CL:0000127; central nervous system neuron / glutamatergic neuron CL:0000679; hippocampal pyramidal neuron; peripheral monocyte/macrophage CL:0000235 (infiltrating).

Biological processes (GO): GO:0006954 (inflammatory response); GO:0002526 (acute inflammatory response); GO:0070498 (IL-1-mediated signaling); GO:0032635/GO:0032611 (IL-6 / IL-1β production); GO:0001774 (microglial activation); GO:0060291/excitatory synaptic plasticity; GO:0007268 (chemical synaptic transmission); BBB dysfunction (GO:0043114 regulation of vascular permeability).

Immune involvement: predominantly innate/autoinflammatory (IL-1/IL-6 axis, microglia), not classic adaptive autoimmunity — antibodies usually absent. This is why IL-1 blockade (anakinra) and IL-6R blockade (tocilizumab) are mechanistically rational and empirically the most promising immunotherapies.

Molecular profiling: the reproducible signal is a CSF/serum cytokine-chemokine signature (↑IL-6, ↑IL-1RA, ↑IL-1β, ↑IL-8, ↑CXCL10, ↑CCL chemokines). No robust FIRES-specific transcriptomic/proteomic/metabolomic dataset yet — a genuine knowledge gap worth a discussions: KNOWLEDGE_GAP note.

Sources: "Fighting autoinflammation in FIRES" PMID:35356746, Clarkson 2019 PMID:30779222, IL-6 neuro review PMC11249726, NORSE immune dysregulation review.

7. Anatomical Structures Affected

• Primary organ / system: brain / central nervous system (UBERON:0000955 brain; UBERON:0001017 CNS). Bilateral, often with fronto-temporal / perisylvian predominance initially.
• Most consistently injured region: hippocampus / mesial temporal lobe (UBERON:0002421 hippocampal formation; UBERON:0002771 medial temporal lobe → chronic mesial temporal sclerosis). Also neocortical (frontal, temporal, insular/perisylvian; UBERON:0016525 insular cortex).
• Chronic structural change: diffuse cerebral atrophy with ventriculomegaly (~49% of chronic cases) and bilateral hippocampal/temporal atrophy (~half) on follow-up MRI (PMC9756623).
• Secondary organ involvement: systemic ICU complications of prolonged SE + anesthesia — respiratory (ventilator dependence, pneumonia), cardiovascular (dysautonomia, propofol-related issues), metabolic/hepatic (from ketogenic diet + anesthetics), immobility complications. These are downstream of critical illness, not primary FIRES targets.
• Tissue/cell level: gray-matter neurons (hippocampal pyramidal, neocortical), reactive astrocytes and microglia; BBB endothelium (UBERON:0001986 endothelium) with increased permeability.
• Subcellular (GO cellular component): synapse GO:0045202 (NMDA-receptor-bearing postsynaptic membrane, GO:0014069); microglial inflammasome machinery (cytoplasm); mitochondria in excitotoxic neurons (GO:0005739).
• Lateralization: typically bilateral, may be asymmetric; hallmark EEG shows multifocal seizures with shifting/migrating foci across both hemispheres.

Sources: PMC9756623.

8. Temporal Development

• Onset: acute / explosive, in a previously healthy person, 24 h–2 weeks after the febrile prodrome resolves. Peak pediatric onset ~7–10 years (any age per 2018 consensus).
• Stages: (1) prodromal febrile illness → (2) acute refractory/super-refractory SE lasting weeks to months (the ICU phase) → (3) chronic drug-resistant epilepsy + neurocognitive sequelae, typically lifelong.
• Progression rate: acute phase is rapid and severe; there is frequently no latent seizure-free "honeymoon" between acute and chronic phases — the epilepsy is continuous.
• Course pattern: acute super-refractory (continuous) → chronic relapsing/refractory epilepsy that is usually static-to-slowly-progressive cognitively.
• Remission: spontaneous remission of the acute SE can occur but is unpredictable; treatment-induced seizure reduction is the goal, rarely full seizure-freedom. Chronic epilepsy generally does not remit.
• Critical window for intervention: strong emerging theme that early immunotherapy (first-line within ~72 h; escalate to anakinra/tocilizumab early) and early ketogenic diet improve outcomes — the therapeutic window is days, not weeks. This "treat early or lose the brain" window is a key actionable claim.

Sources: Wickstrom 2022 consensus PMID:35951466, PMC9756623.

9. Inheritance and Population

• Epidemiology: rare. In Germany, prevalence ≈ 1/100,000 and annual incidence ≈ 1/1,000,000 in children/adolescents (Orphanet). Roughly ~100+ cases published worldwide; global data sparse.
• For dismech Prevalence: measure_type: POINT_PREVALENCE, prevalence_class: BAND_1_9_PER_1000000 or BELOW_1_IN_1000000 depending on framing; rate_per_100000 ≈ 1.0 (prevalence) — and a separate ANNUAL_INCIDENCE record at rate_per_100000 ≈ 0.1 (1/1,000,000). Do not conflate the two.
• Inheritance pattern: not heritable / not Mendelian. No AD/AR/X-linked/mitochondrial pattern; sporadic. Susceptibility is multifactorial with innate-immune (IL1RN) modifiers. Penetrance/expressivity/anticipation/founder/consanguinity/carrier-frequency fields are not applicable.
• Demographics: predominantly school-age children, with reports across all ages since the consensus broadened it. Possible male predominance (modest, per case series). No strong ethnic/geographic clustering established (AERRPS literature is Japanese, likely ascertainment rather than true predisposition).

Sources: Orphanet, Dovepress prevalence/impact review.

10. Diagnostics

FIRES is fundamentally a diagnosis of exclusion + a compatible clinical picture (refractory SE after recent fever, no cause found). Consensus (Wickstrom 2022, PMID:35951466) emphasizes broad, rapid workup.

• EEG (essential): early fronto-temporal spike-and-wave; evolving to multifocal seizures with migrating foci, diffuse delta-theta slowing; may show the extreme delta brush pattern (shared with anti-NMDAR encephalitis). Continuous EEG monitoring is mandatory to track (super-)refractory SE. (LOINC-codable; electrophysiology.)
• MRI: often normal early (~61% normal at presentation — PMC9756623), which supports the diagnosis; later shows hippocampal T2/FLAIR signal → mesial temporal sclerosis, and progressive atrophy/ventriculomegaly. (RadLex/Radiopaedia.)
• CSF: mild lymphocytic pleocytosis (>50%), usually normal glucose, negative infectious PCR/culture, and elevated pro-inflammatory cytokines/chemokines (research/specialty assays). Send autoimmune encephalitis antibody panel (serum + CSF) — usually negative, but must exclude antibody-mediated NORSE.
• Blood: inflammatory markers; rule out systemic infection, HLH/macrophage-activation (ferritin, triglycerides — a reported FIRES mimic/overlap), metabolic and toxicologic causes.
• Genetic testing: epilepsy gene panel / WES/WGS is recommended in the NORSE/FIRES workup to exclude monogenic mimics (e.g., PCDH19, POLG, SCN1A, mitochondrial disease) — not because a FIRES gene exists, but to rule out a look-alike. Mitochondrial testing where indicated. CMA/karyotype normal.
• Differential diagnosis (must rule out): infectious/viral encephalitis; anti-NMDAR and other autoimmune encephalitides; mitochondrial encephalopathy (POLG, MELAS); genetic epileptic encephalopathies (Dravet/SCN1A, PCDH19); CNS vasculitis; toxic/metabolic SE; HLH/MAS-associated SE. FIRES's distinguishing features: normal prior development, obligate preceding fever, absence of identified cause, and the innate-cytokine signature.
• Screening: no population screening — too rare, no biomarker with predictive value pre-onset.

Sources: Wickstrom 2022 PMID:35951466, PMC9756623.

11. Outcome / Prognosis

Blunt truth: FIRES is one of the worst outcomes in pediatric neurology.

• Mortality: up to ~12–30% (acute-phase death, often from super-refractory SE and its ICU complications).
• Epilepsy: near-universal in survivors — "among 66 of the 68 survived, 63 continued to have epilepsy refractory to any type of treatment" (PMC9756623). So >90% of survivors → chronic drug-resistant epilepsy.
• Cognition: roughly a thirds distribution — ~1/3 normal-to-borderline, ~1/3 mild–moderate intellectual disability, ~1/3 severe ID / vegetative. Overall ~66–100% of survivors are left developmentally disabled (Orphanet/NORD).
• Prognostic factors (emerging): longer/deeper barbiturate coma and longer SE duration → worse cognitive outcome; earlier immunotherapy and earlier ketogenic diet → better outcome. Higher/earlier cytokine burden may portend worse course. No validated prognostic biomarker yet.
• Morbidity / QoL: severe — lifelong care needs, special education, motor/language deficits, behavioral/psychiatric comorbidity, and high family/caregiver burden.

Sources: Orphanet, NORD, PMC9756623.

12. Treatment

No cure; management is a two-front war — stop the seizures and cool the inflammation — with early, aggressive escalation. The 2022 international consensus (Wickstrom et al., PMID:35951466, 85 consensus statements) is the anchor.

A. Anti-seizure / anesthetic (acute SE control) - Standard SE ladder: benzodiazepines → IV ASMs (levetiracetam, valproate, phenytoin/fosphenytoin) → anesthetic/burst-suppression coma (midazolam, barbiturates/pentobarbital, ketamine, propofol). Caveat: prolonged barbiturate coma correlates with worse cognition — a therapy whose cure edges into harm. - MAXO: MAXO:0000058 (pharmacotherapy) / antiseizure pharmacotherapy; anesthesia. - Cannabidiol (Epidiolex): promising in both phases — case series of 7 children, 6/7 improved in seizure frequency/duration (Gofshteyn et al. 2017, J Child Neurol; PMID:27655472); acute-phase reports of SE resolution within days (Fetta 2023, Epilepsia Open, doi:10.1002/epi4.12740, verify PMID). CHEBI: cannabidiol CHEBI:69478. - Other ASMs reported ad hoc (cenobamate, perampanel, topiramate) in the chronic phase — anecdotal.

B. Ketogenic diet (KD) — a signature FIRES therapy - Landmark: Nabbout et al. 2010, Epilepsia (doi:10.1111/j.1528-1167.2010.02703.x, verify PMID) — 4:1 KD in 9 FIRES children, efficacious in 7, with seizure cessation 2–4 days after ketonuria / 4–6 days after diet onset. Now a recommended early adjunct (watch for propofol interaction → propofol infusion syndrome). MAXO: MAXO:0000088 (dietary intervention) / ketogenic diet.

C. Immunotherapy (mechanistically the most rational) - First-line, start within ~72 h: high-dose corticosteroids (MAXO/CHEBI corticosteroid), IVIG, and/or plasma exchange. MAXO: MAXO:0000759 (immunosuppressive therapy); plasmapheresis. - Second-line, escalate early in cryptogenic FIRES: - Anakinra (recombinant IL-1 receptor antagonist) — the most evidence-backed targeted therapy, born from the mechanism itself. First reported by Kenney-Jung et al. 2016, Ann Neurol (doi:10.1002/ana.24806, verify PMID): CSF cytokines normalized on treatment. In one series, 11/15 children had >50% seizure reduction at 1 week (PMC9756623); early use → shorter ICU stay. Long-term neuropsych outcomes can still be poor despite anakinra (Frontiers Neurol 2023). - Tocilizumab (IL-6 receptor monoclonal antibody) — effective in some anakinra-refractory cases (Stredny et al. 2020, Child Neurol Open, doi:10.1177/2329048X20979253, verify PMID); and vice versa — anakinra works in some tocilizumab-refractory cases even with normal IL-1β (Frontiers Immunol 2026). MAXO: MAXO:0000759 immunomodulation; therapeutic_modality: MONOCLONAL_ANTIBODY for tocilizumab. - Chronic-phase case series: anakinra/tocilizumab gave partial seizure reduction (20–50%) in some, no seizure-freedom (Seizure 2022, PMID:35759951). - Others (rituximab, tacrolimus, canakinumab, cyclophosphamide) — inconsistent/unclear benefit.

D. Other / experimental: vagus nerve stimulation and epilepsy surgery in selected chronic drug-resistant cases; therapeutic hypothermia (largely abandoned); intrathecal/other anti-cytokine strategies under study. Active clinical trials exist (e.g., KD for SRSE, NCT07496749 — verify) — search ClinicalTrials.gov for current anakinra/tocilizumab/KD FIRES trials.

Pharmacogenomics: none FIRES-specific; the closest thing to "genotype-guided therapy" is the conceptual match of IL-1RA-deficiency → anakinra, i.e., mechanism-guided rather than pharmacogenomic.

Sources: Wickstrom 2022 PMID:35951466, Kenney-Jung 2016, Nabbout 2010 KD, Gofshteyn 2017 CBD PMID:27655472, Anakinra long-term outcomes, Chronic-phase series PMID:35759951.

13. Prevention

Largely not applicable / not feasible — you can't screen for or vaccinate against a syndrome whose trigger is "some ordinary fever" in a genetically-unpredictable host.

• Primary prevention: none. No way to identify at-risk children pre-onset; routine childhood vaccination reduces some febrile infections generally but isn't a FIRES-specific strategy.
• Secondary prevention (early detection/treatment): the real lever — early recognition of NORSE/FIRES and rapid escalation to immunotherapy + KD within days is effectively "secondary prevention" of the devastating chronic phase. This is the consensus's central practical message.
• Tertiary prevention: manage chronic epilepsy, rehab (PT/OT/speech), neuropsychology, avoid prolonged barbiturate coma, prevent ICU complications.
• Genetic counseling / carrier / prenatal screening: not applicable — sporadic, non-Mendelian; recurrence risk to siblings is not meaningfully elevated.

Sources: Wickstrom 2022 PMID:35951466.

14. Other Species / Natural Disease

• Taxonomy: described in humans (NCBITaxon:9606) only.
• Natural animal disease: none reported — there is no recognized spontaneous FIRES equivalent in companion animals or wildlife (OMIA has no FIRES entry). Veterinary relevance: nil.
• Comparative biology: the mechanistic pieces (fever → IL-1β/IL-6 neuroinflammation → seizure) are evolutionarily conserved and studied in rodent inflammation-induced seizure / epileptogenesis models, but no animal naturally develops the FIRES syndrome.
• Zoonosis / cross-species transmission: not applicable (FIRES is not transmissible; the antecedent infections may be common human pathogens but FIRES itself is a host immune response).

15. Model Organisms

No faithful animal model of FIRES exists — a genuine translational gap, and worth a discussions: HUMAN_MODEL_MISMATCH entry rather than a claim of recapitulation.

• Closest surrogates (mechanistic, not disease-faithful):
• Rodent inflammation-driven seizure / epileptogenesis models — systemic or intracerebral LPS, IL-1β, or poly(I:C) to model fever/infection-triggered hyperexcitability; kainate/pilocarpine SE models with an inflammatory "second hit." These reproduce the IL-1β → NMDA-potentiation → seizure node but not the explosive, super-refractory, previously-healthy-child syndrome.
• IL1RN-related manipulations (IL-1RA knockout / IL-1β overexpression) speak to the anti-inflammatory-braking hypothesis but are not "FIRES mice."
• Genetic models: none purpose-built for FIRES (no causal gene to knock in). Il1rn-null mice exist for autoinflammation broadly and are conceptually relevant to the IL-1RA-deficiency hypothesis.
• In vitro / patient-derived: patient CSF cytokine assays and cell-based IL-1R signaling assays (as in Clarkson 2019) are the main experimental system; iPSC-derived neuron/microglia co-cultures are a logical but not-yet-established avenue.
• Model limitation (the crux): no model captures the whole-syndrome convergence — the specific human host-susceptibility + common-infection trigger + super-refractory course. Applications are limited to dissecting the cytokine-hyperexcitability loop, not the syndrome.

Resources: MGI (Il1rn, Il6 alleles), rodent SE/neuroinflammation literature.

Curation notes & flagged gaps for the dismech entry

• Model this as an immune/inflammatory epileptic encephalopathy, not a gene disorder. The natural conforms_to target is the epilepsy convergence module — epilepsy_excitation_inhibition_imbalance#Excitation-Inhibition Imbalance — with FIRES supplying the upstream inflammatory driver (IL-1β/IL-6 → NMDA potentiation + GABA suppression) rather than a channel variant. Consider whether a dedicated neuroinflammation/autoinflammatory-seizure module is warranted; if one is ever built, FIRES + antibody-mediated NORSE would be natural conformers.
• Pivotal node to curate: functional IL-1RA deficiency → unopposed IL-1β signaling (Clarkson 2019, PMID:30779222) — this is the mechanistic hinge and the therapeutic rationale for anakinra, so it deserves its own pathophysiology node with the anakinra treatment linked via target_mechanisms.
• Two separate Prevalence records (point prevalence ~1/100,000 vs annual incidence ~1/1,000,000) — don't merge; different measure_type.
• Evidence-source tagging: most treatment evidence is small HUMAN_CLINICAL case series (low N); the IL-1RA functional work is IN_VITRO cell-based assay + human samples; rodent inflammation-seizure work is MODEL_ORGANISM. Split accordingly.
• PMIDs to verify before quoting (I could confirm the paper but not independently pin the PMID via search): Hirsch 2018 consensus (doi:10.1111/epi.14016), Kenney-Jung 2016 (doi:10.1002/ana.24806), Nabbout 2010 KD (doi:10.1111/j.1528-1167.2010.02703.x), Fetta 2023 CBD (doi:10.1002/epi4.12740), Stredny 2020 tocilizumab (doi:10.1177/2329048X20979253), Fisher 2025 CSF1R (doi:10.1111/epi.18538). Confirmed PMIDs: 30779222 (Clarkson), 35951466 (Wickstrom), 23066759 (Appenzeller), 27655472 (Gofshteyn CBD), 35356746 (autoinflammation review), 35759951 (chronic-phase anakinra/tocilizumab series). Run just fetch-reference on each and verify snippets before committing.

Primary sources cited: Hirsch 2018 consensus (Epilepsia) · Wickstrom 2022 management consensus (PMID:35951466) · Clarkson 2019 IL-1RA deficiency (PMID:30779222) · Appenzeller 2012 gene-negative (PMID:23066759) · Kenney-Jung 2016 anakinra · Nabbout 2010 ketogenic diet · Gofshteyn 2017 cannabidiol (PMID:27655472) · Chronic-phase anakinra/tocilizumab series (PMID:35759951) · "Fighting autoinflammation in FIRES" (PMID:35356746) · Fisher 2025 CSF1R (Epilepsia) · Lit review + 2 cases (PMC9756623) · Orphanet 163703 · NORD/MONDO FIRES.

That's the whole map, Harry. The one-sentence version if you're skimming: FIRES is a fever that lights a match in a brain whose anti-inflammatory fire extinguisher (IL-1RA) is functionally busted — so the innate-immune blaze and the seizures feed each other into weeks of unstoppable status epilepticus, and the survivors pay for it for life. The whole thing points at IL-1/IL-6 blockade as the rational therapy, which is exactly where the anakinra/tocilizumab evidence is pooling. Curate it as an inflammatory epileptic encephalopathy hanging off the E/I-imbalance module, not as a gene disorder — there is no gene.