Febrile seizure

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  • See also

    Seizures acute management 
    Febrile child

    Key points

    1. Most febrile seizures are benign and do not require further investigation
    2. Management includes identifying and managing the source of infection
    3. Antipyretics do not prevent febrile convulsions

    Background

    • Definition: a seizure associated with a fever (of at least 380C) in a young child without any of the following:
      • central nervous system infection
      • electrolyte imbalance
      • a history of afebrile seizures
    • Usually occur between 6 months and 6 years of age
    • Normally associated with simple viral infections
    • Younger children are more likely to have a further febrile seizure
      • 50% risk of recurrence in 1-year-old child
      • 30% risk of recurrence in 2-year-old child

    Genetics and febrile seizures

    • Background prevalence risk of 1 in 30
      • Rises to 1 in 5 where one sibling is affected
      • Rises to 1 in 3 if both parents and a previous child have had previous febrile seizures
    • No single susceptibility gene for febrile seizure is known
    • Genetic testing may be recommended in specific higher-risk groups, eg prolonged febrile seizures in children less than 18 months
    • Genes have been identified in families with "genetic epilepsies with febrile seizures plus spectrum" (GEFS+)

    Assessment

    History

    • Onset of illness
    • Determine source of the fever eg viral, gastroenteritis, UTI
    • Seizure characteristics
      • duration
      • generalised versus focal features
      • length of post ictal period
      • return to neurological baseline
    • Screen for alternative causes of presentation, eg seizure mimickers, cardiac dysrhythmia, underlying metabolic syndromes
    • History of neurological conditions
    • History of developmental delay or regression
    • Family history of febrile seizures, epilepsy or sudden cardiac death

    Examination

    • Identify source of infection
    • Neurological examination
      • Confirm return to neurological baseline
      • Red flags suggestive of CNS infection
        • complex febrile seizure
        • meningism (bulging fontanelle, neck stiffness, photophobia)
        • prolonged postictal altered consciousness (>1 Hour)
      • Neurocutaneous stigmata, eg facial port-wine stain, facial angiofibroma, hypopigmented macules, café au lait spots

    Classification of febrile seizures

    Simple febrile seizure Complex febrile seizure
    Generalised tonic-clonic, and

    Duration <15 min, and

    Complete recovery <1 hour, and

    Does not recur within same illness

    Afebrile febrile seizure: as above but occurring during an acute infectious illness without a documented fever
    Focal features, or

    Duration >15 min, or

    Persistent altered mental status (>1 hour), or

    Recurrence within same illness

    Prolonged febrile seizure: as above with duration >30 minutes - may be associated with genetic epilepsy syndromes

    Management

    Investigations

    • A simple febrile seizure does not require additional investigations beyond any required for investigation of the fever
      • Additional blood tests and neuroimaging are low yield and risk exposing the child to unnecessary painful procedure and/or radiation
    • Targeted investigations are recommended in atypical presentations or with complex febrile seizures
      • Exclude provoked seizure: BGL, serum electrolytes
      • Exclude seizure mimicker: ECG
    • Investigations should be performed in children who appear seriously unwell, see febrile child. Red flags for serious infection include
      • Complex febrile seizures
      • Persistent altered mental status (>1 hour)
      • Signs of sepsis, meningitis or encephalitis
      • Incomplete immunisation against Haemophilus influenzae B or Streptococcus pneumoniae
    • In a complex febrile seizure, consider CNS imaging after consultation with a senior doctor

    Treatment

    • Treat the seizure if duration ongoing after 5 minutes, see afebrile seizures
    • Manage the underlying cause of the fever
      • Children with simple febrile seizures have the equivalent risk of serious bacterial infection as those with fever alone
    • Ongoing treatment with antiepileptic drugs is not routinely recommended

    Consider consultation with local paediatric team when

    • Complex febrile seizure
    • Concern for serious bacterial infection as cause of febrile seizure

    Consider transfer when

    • Respiratory or haemodynamic compromise
    • Prolonged febrile seizure
    • Persistent altered mental status (>1 hour)
    • Children requiring care above the level of comfort of the local hospital

    For emergency advice and paediatric or neonatal ICU transfers, see Retrieval Services

    Consider discharge when

    • Returned to normal neurological state following simple febrile seizure
    • Underlying illness has been assessed and managed appropriately
    • All families should receive education prior to discharge which includes:
      • Seizure first aid
      • Febrile seizure handout
      • If seizure >5 minutes, consider providing emergency medication management plan and parent midazolam training
    • Arrange follow-up if required for the underlying illness
    • Consider outpatient paediatric follow-up, see below

    Consider outpatient follow-up when

    • Risk factors are present for development of epilepsy
      • Prolonged febrile seizure
      • Family history of epilepsy
      • Neurocutaneous stigmata identified on examination
      • Recurrent complex febrile seizures
      • Developmental impairment
    • Further investigations may include EEG, neuroimaging and genetic testing
    • Genetic testing may be recommended in higher risk groups
      • Prolonged febrile convulsions in child <18 months
      • Febrile seizures in children >6 years
      • Associated developmental impairment

    Parent information

    Febrile seizures (Vic)
    Febrile convulsion (NSW)
    Febrile convulsions (QLD)
    Febrile convulsions (WA)

    First aid for seizures (Vic)
    First aid during seizures (NSW)
    First aid for seizures (QLD)
    First aid for seizures (WA)

    Midazolam for seizures (Vic)
    Zyamis Product Information (TGA)

    See Also

    Paediatric Epilepsy Network New South Wales (PENNSW)

    Last updated February 2026

    Reference list

  • Reference List

    1. Lee WL, Ong HT. Afebrile seizures associated with minor infections: comparison with febrile seizures and unprovoked seizures. Pediatr Neurol. 2004;31(3):157-164.
    2. Mewasingh, L et al. Febrile Seizure. Retrieved from https://bestpractice.bmj.com/topics/en-gb/566 (viewed 13 May 2019)
    3. Millichap, JJ et al. Clinical features and evaluation of febrile seizures. Retrieved from https://www.uptodate.com/contents/clinical-features-and-evaluation-of-febrile-seizures?search=febrile%20seizure&source=search_result&selectedTitle=1~134&usage_type=default&display_rank=1 (viewed 15 May 2019)
    4. Millichap, JJ et al. Treatment and prognosis of febrile seizures. Retrieved from https://www.uptodate.com/contents/treatment-and-prognosis-of-febrile-seizures?search=febrile%20seizure&source=search_result&selectedTitle=2~134&usage_type=default&display_rank=2 (viewed 15 May 2019)
    5. Paediatric Epilepsy Network. Febrile seizures. Retrieved fromhttp://www.pennsw.com.au/clinicians/syndromes/febrile-seizures (viewed May 13 2019)
    6. Patel, N et al. Febrile Seizures. BMJ. 2015. 351:h4240 [DOI: https://doi.org/10.1136/bmj.h4240, viewed May 2019]