Paeds · neurology-neurodisability-and-neuromuscular
Febrile seizures
Also known as Febrile seizure · Febrile convulsion · Simple febrile seizure · Complex febrile seizure · Febrile status epilepticus · GEFS+ (generalised epilepsy with febrile seizures plus)
Fellowship guide to febrile seizures: the age-locked definition (6 months to 5 years with fever, no CNS infection, no prior afebrile seizure), the simple-versus-complex split that drives every decision, the reassuring prognosis, the acute termination of a prolonged convulsion with a benzodiazepine, the case against routine antiepileptic prophylaxis and against antipyretics as prevention, the lumbar-puncture thresholds of the 2011 AAP guideline, and the FEBSTAT evidence linking febrile status epilepticus to hippocampal injury.
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Red flags
- A convulsion with fever in a child under 6 months or over 5 years is NOT a febrile seizure - actively exclude meningitis, encephalitis, electrolyte disturbance, hypoglycaemia, and an inherited epilepsy
- A febrile seizure lasting over 5 minutes needs active termination: IV lorazepam 0.1 mg/kg (max 4 mg) or buccal midazolam 0.5 mg/kg (max 10 mg); febrile status epilepticus beyond 30 minutes is a neurocritical emergency
- A child under 12 months with fever and a seizure needs a low threshold for lumbar puncture to exclude bacterial meningitis, because meningeal signs are unreliable in infants
- Focal onset, duration over 15 minutes, or recurrence within 24 hours marks a complex febrile seizure with a higher epilepsy risk - the workup and counselling change
- A prolonged postictal state, bulging fontanelle, petechial rash, or a focal neurological deficit argues against simple febrile seizure and demands exclusion of meningitis, encephalitis, or a structural lesion
- Prior antibiotic exposure can mask meningeal signs - lower the threshold for lumbar puncture in a febrile child who has already received antibiotics
- Developmental delay, asymmetric or prolonged convulsions, or a family history of Dravet syndrome points to a genetic epilepsy such as SCN1A-related disease, not a simple febrile seizure
Life stages
Care settings
Clinical exam formats
Board mappings
- Defines a febrile seizure using the age-locked, fever-locked, exclusion-based criteria
- Separates simple from complex febrile seizures and lists the features of febrile status epilepticus
- Resuscitates a prolonged convulsion with a benzodiazepine and excludes meningitis before calling it simple
- Defends the case against routine antiepileptic and antipyretic prophylaxis using the AAP and Cochrane evidence
- Applies the 2011 AAP lumbar-puncture thresholds to the infant under 12 months and the child pre-treated with antibiotics
- Counsels accurately on recurrence risk, epilepsy risk, and the reassuring prognosis of simple febrile seizures
- Definition and simple-versus-complex classification of febrile seizures
- Acute termination of a prolonged febrile seizure and the febrile status epilepticus pathway
- Investigation strategy, lumbar-puncture thresholds, and the case against prophylaxis
- Resuscitates and reassures the febrile, convulsing child while excluding meningitis at the bedside
- Communicates the benign prognosis and the recurrence safety-net to an anxious family
- Justifies non-treatment and observation over investigation for a simple febrile seizure
- Level 1: Recognition of a simple febrile seizure and exclusion of meningitis
- Level 2: Acute management of a prolonged convulsion and selective investigation
- Level 3: Long-term counselling on recurrence, epilepsy risk, and the avoidance of prophylaxis
- Definition, age range, and simple-versus-complex classification of febrile seizures
- Lumbar-puncture thresholds and the role of EEG and neuroimaging after a febrile seizure
- Evidence against continuous and intermittent antiepileptic prophylaxis
- Assessment of the febrile, postictal child and the signs that exclude simple febrile seizure
- Interpretation of the recurrence and epilepsy risk factors for family counselling
- Structured explanation of acute termination and the observation pathway
- American Academy of Pediatrics 2011 guideline for the neurodiagnostic evaluation of the child with a simple febrile seizure
- AAP 2008 guideline for the long-term management of the child with simple febrile seizures
- Acute seizure termination and the avoidance of routine prophylaxis
- Recognition of the convulsing, febrile child as a time-critical assessment and a common benign diagnosis
- Staged benzodiazepine termination of a prolonged febrile seizure and escalation to second-line therapy
- Family communication around prognosis, recurrence, and the harm of unnecessary prophylaxis
- Canadian Paediatric Society approach to the febrile convulsion and the avoidance of over-investigation
- Acute termination of febrile status epilepticus and selective lumbar puncture in infants
- Counselling on the benign prognosis and the evidence against prophylaxis
Overview & Definition
Picture the 18-month-old brought to the emergency department in the arms of a frightened parent after a generalised convulsion that lasted two minutes and began with a fever that morning. The child is now alert, febrile to 39.2 degrees Celsius, and has a clear viral upper-respiratory infection. That child carries the entire teaching point of febrile seizures: a frightening event with a reassuring prognosis, where the task is to confirm the diagnosis, exclude meningitis, terminate any ongoing convulsion, and resist the impulse to over-investigate or over-treat. [1]
A febrile seizure is defined by four locked criteria. The child is aged between 6 months and 60 months (5 years). There is a fever, taken as a temperature over 38 degrees Celsius. There is no evidence of a central nervous system infection. And the child has no history of a prior afebrile seizure and no defined acute neurological cause. A convulsion with fever that falls outside any one of these criteria is not a febrile seizure and demands a different diagnostic path. [1] [2]
Febrile seizures are the most common neurological disorder of early childhood, affecting between 2 and 5 per cent of children in Western populations, with a peak incidence between 12 and 18 months of age and a slight male predominance. They are a developmental phenomenon of the immature brain, and they are benign. The teaching challenge is to hold three ideas together at once: the event is terrifying for families, the underlying diagnosis is usually benign, and a small minority of children have a dangerous mimic or a prolonged convulsion that needs active treatment. [2] [3]
References12ShowHide
- [1]Subcommittee on Febrile Seizures, American Academy of Pediatrics Neurodiagnostic evaluation of the child with a simple febrile seizure. Pediatrics, 2011.PMID 21285335
- [2]Steering Committee on Quality Improvement and Management, Subcommittee on Febrile Seizures, American Academy of Pediatrics Febrile seizures: clinical practice guideline for the long-term management of the child with simple febrile seizures. Pediatrics, 2008.PMID 18519501
- [3]Baumann RJ Technical report: treatment of the child with simple febrile seizures. Pediatrics, 1999.PMID 10353983
- [4]McIntyre J, Robertson S, Norris E, Appleton R, Whitehouse WP, Phillips B, Martland T, Berry K, Collier J, Smith S, Choonara I Safety and efficacy of buccal midazolam versus rectal diazepam for emergency treatment of seizures in children: a randomised controlled trial. Lancet, 2005.PMID 16023510
- [5]Offringa M, Newton R, Nevitt SJ, Vraka K Prophylactic drug management for febrile seizures in children. Cochrane Database Syst Rev, 2021.PMID 34131913
- [6]Rosenbloom E, Finkelstein Y, Adams-Webber T, Kozer E Do antipyretics prevent the recurrence of febrile seizures in children? A systematic review of randomized controlled trials and meta-analysis. Eur J Paediatr Neurol, 2013.PMID 23702315
- [7]Berg AT, Shinnar S Predictors of recurrent febrile seizures: a metaanalytic review. J Pediatr, 1990.PMID 2137875
- [8]Lewis DV, Voyvodic J, Shinnar S, et al. Hippocampal sclerosis and temporal lobe epilepsy following febrile status epilepticus: The FEBSTAT study. Epilepsia, 2024.PMID 38606600
- [9]Hesdorffer DC, Shinnar S, Lewis DV, et al. Design and phenomenology of the FEBSTAT study. Epilepsia, 2012.PMID 22742587
- [10]Epstein LG, Shinnar S, Hesdorffer DC, et al. Human herpesvirus 6 and 7 in febrile status epilepticus: the FEBSTAT study. Epilepsia, 2012.PMID 22954016
- [11]Hesdorffer DC, Shinnar S, Lax DN, et al. Risk factors for subsequent febrile seizures in the FEBSTAT study. Epilepsia, 2016.PMID 27265870
- [12]Kimia AA, Capraro AJ, Hummel D, Johnston P, Harper MB Utility of lumbar puncture for first simple febrile seizure among children 6 to 18 months of age. Pediatrics, 2009.PMID 19117854