• Prevalence of 2 to 4% with peak age of 18 to 24 months
  • Seen from 6 months to 6 years
  • Defined as a seizure with temperature >38 C without a central nervous system infection
  • Classified into two categories:

  • Associated with increased risk: history of febrile seizures in a first or second degree relative, day care attendance, neonatal discharge greater than 28 days, and slow neurological development
    • Any one of these factors increased the risk from 2 to 4% to 6 to 10%.
    • 2 risk factors the incidence increases to 28% (Bethune 1993)


  • Clinical
    • The diagnostic evaluation should be directed at establishing the cause of the fever rather than the seizure
    • A clinical practice guideline for neurodiagnostic evaluation of the child with a simple febrile seizure has been published by the American Academy of Pediatrics (AAP, 2011)
      • Apply to neurologically healthy children 6 to 60 months presenting within 12 hours of a simple febrile seizure

  • Laboratory
    • Patients with a simple febrile seizure do not have an increased incidence of bacteremia or UTI
    • Evaluation for a UTI, bacteremia or pneumonia should be based on the same criteria for patients with a fever but without a febrile seizure
  • Lumbar Puncture
    • A lumbar puncture should only be done if meningitis is suspected (e.g. no return to baseline after appropriate interval)
    • In most studies, everyone with meningitis was clinically ill appearing or had obvious meningeal signs
      • A study of 503 meningitis patients determined that 23% (115) had a seizure prior to diagnosis. 105/115 (91.3%) were obtunded or comatose. Of the remaining 10 patients, 8 had irritability and nuchal rigidity and 2 had complete febrile seizures. (Green 1993)
    • In the past, it has been recommended that a lumbar puncture should be considered in patients with a complex febrile seizure
      • A 2017 study included 2,839 patients presenting with a complex febrile seizure of which 31% had a lumbar puncture (Guedj 2017)
        • Overall rate of bacterial meningitis was 0.7%
        • Rate of bacterial meningitis in patients without an examination suggestive of meningitis was 0.0%
      • Neuroimaging
        • There is no role for a head CT or MRI in simple febrile seizures
        • If the patient had a complex seizure, a head CT or MRI may be considered
          • The incidence of a significant finding in this group is between 5 to 10%


  • Supportive care such as antipyretics for fever or antibiotics for an identified bacterial infection are generally the only treatment needed
  • Antipyretics
    • Many clinicians recommend the use of “around the clock” alternating antipyretics such as Acetaminophen or Ibuprofen
    • In one study, Tylenol q6h at 10 mg/kg PR for the first 24 hours following the initial seizure was associated with a decreased rate of recurrence when compared to children who did not receive antipyretics (Murata, 2018)
  • Antiepileptics
    • Phenobarbital (Camfield 1980) and Sodium Valproate (Mamelle 1984) may decrease the incidence of future febrile seizures
    • They are not routinely prescribed because of their long-term cognitive effects
    • Rectal diazepam is sometimes prescribed for those with recurrent febrile seizures
      • For patients with 2 or more risk factors for recurrence, giving rectal Diazepam at the onset of fever has been shown to decrease the risk of recurrence to 12% (Knudson 1985)
      • Patients may present with an altered mental status due to the Diazepam making the evaluation of the need for a lumbar puncture difficult


  • Simple febrile seizures can be safely discharged after the parents have been counseled
  • Complex febrile seizures may require a more extensive evaluation and a neurology consult; admission should be considered in this group


  • Recurrence Risk
    • The primary risk of simple febrile seizures is recurrence in approximately 1/3 of patients (14% at 6 months, 25% at 12 months and 30% at 24 months (Berg 1997)

    • The lower the temperature that the patient has their febrile seizure at, the greater the chance or recurrence
      • The incidence of recurrence if the febrile seizure occurs at 101 degrees is 35% and decreases in a linear fashion to 13% for a temperature of greater than 105 degrees (Berg 1992)
    • There are data to support that the seizure occurs early on in the febrile event.
    • There are no data to support the commonly held belief that a high rate of rise in temperature causes febrile seizures
  • Epilepsy Risk
    • The risk of epilepsy after a simple febrile seizure (1-2%) has been shown to be only slightly greater than the risk in the general population (0.5%)
      • This risk increased in those with a family history of epilepsy, recurrence of febrile seizures and complex febrile seizures (Pavlidou 2013)
  • Cognitive Effects


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