Febrile seizure


  • Occur in 2-5% of American children before age 5[1]
  • 50% of patients never have temperature >39
  • Febrile seizures do not increase the risk of serious bacterial illness


  • 2-3% chance of developing epilepsy (1% for general population)
  • 50% of patients <12 mo will have another simple febrile seizure
  • 30% of patients >12 mo will have another simple febrile seizure

Clinical Features

Simple Febrile Seizure

  • Age 6mo-5yr, with majority occurring between 12mo-18mo
  • Single seizure in 24hr
  • Duration <15min
  • Generalized with no focal features
  • Returns to neurologic baseline and has normal neuro exam after brief post-ictal period

Complex Febrile Seizure

  • Any exception to above
  • May indicate more serious disease process

Differential Diagnosis

Pediatric seizure

Pediatric fever


  • The key is to distinguish between simple febrile seizure secondary to minor illness vs. seizure from serious central nervous system infection, which may also present with fever and seizure.
  • Glucose in all patients

Simple febrile seizure

Complex febrile seizure

Algorithm for the differentiation between simple and complex febrile seizures. Guidelines for evaluation of each.


Initial management of pediatric status epilepticus

Timeline General Considerations Seizure Treatment
0-5 minutes
  • Supportive care
    • ABC's
    • Maintain airway; suction, jaw thrust
    • Provide O2 via positive pressure ventilation with BVM/Mapleson
      • Likely apneic/hypoventilating/hypercapneic
      • Only apply CPAP or a non-rebreather if patient stops seizing and has adequate chest rise
  • Establish IV/IO access
  • Check blood glucose
  • If fever, acetaminophen 15 mg/kg rectally
  • Benzodiazepine: first dose
    • IV/IO access established
      • Lorazepam 0.1 mg/kg IV (max 4 mg) if IV/IO access, OR
      • Diazepam 0.2 mg/kg IM (max 10 mg) if no access
    • IV or IO access not achieved within 3 minutes:
      • Buccal midazolam 0.2 mg/kg (max 10 mg), OR
      • IM midazolam 0.2 mg/kg (max 10 mg), OR
      • Rectal diazepam (Diastat gel or injection solution given rectally) 0.5 mg/kg (max 20 mg)
5-10 minutes
  • Give antibiotics if concern for sepsis or meningitis
  • POC electrolytes, if available
  • Benzodiazepine: second dose
10-15 minutes
  • All equally efficacious for status epilepticus
  • Levetiracetam is preferred given quick administration, favorable side effect profile, and less drug interactions
  • Do not combine Phenytoin and Fosphenytoin
  • Antiepileptic: first therapy
    • Levetiracetam 60 mg/kg IV/IO (max 4500mg) over 5 min, OR
    • Fosphenytoin^ 20 mg PE/kg IV/IO (max 1500mg) over 10 min, OR
    • Valproate 40 mg/kg IV/IO (max 3000mg) over 10 min, OR
    • Phenobarbital 20 mg/kg IV/IO, (max 1 g) over 20 min, (expect respiratory depression with apnea)¥
15-30 minutes
  • Consider intubation, if not already performed
    • Consider NG tube to decompress stomach prior to intubation
  • Pediatric neurology consultation
  • Antiepileptic: second therapy (if medication not already given)
    • Fosphenytoin^ 20 mg PE/kg IV/IO (max 1500mg) over 10 min, OR
    • Valproate 40 mg/kg IV/IO (max 3000mg) over 10 min, OR
    • Phenobarbital 20 mg/kg IV/IO (max 1 g) over 20 min
      • 10 mg/kg if phenobarbital already given, OR
    • Levetiracetam 60 mg/kg IV/IO (max 4500mg) over 5 min
  • If isoniazid toxicity suspected, pyridoxine
    • Infants (<1 year): 100 mg IV or IO in
    • Otherwise 70 mg/kg IV or IO (max = 5 g)
>30 minutes
  • Intubate patient, if not already performed
  • Consult referral site / PICU for admission and continuous EEG
  • Antiepileptic: third therapy
    • Midazolam 0.2mg/kg IV bolus (max 10mg), followed by 0.2mg/kg/hr (max 10mg/hr) infusion drip
    • Increase infusion rate by 0.2mg/kg/hr (max 10mg/hr) every 10 minutes until burst suppression or max dose of 2mg/kg/hr (max 100mg/hr)

^May be ineffective for toxin-induced seizures and contraindicated in cocaine toxicity

Seizure Stopped



  • Simple febrile seizure if patient at baseline
    • Follow-up in 1-2d
    • Around-the-clock acetaminophen may prevent seizure recurrence in the same febrile episode[3]
  • Complex febrile seizure if patient well-appearing, work-up normal
    • Follow-up in 24hr


  • Ill-appearing
  • Lethargy beyond postictal period

See Also


  1. https://www.ninds.nih.gov/disorders/patient-caregiver-education/fact-sheets/febrile-seizures-fact-sheet
  2. Baxter P. et al. Pyridoxine‐dependent and pyridoxine‐responsive seizures. Developmental Medicine & Child Neurology 2001, 43: 416–42
  3. Murata et al. Acetaminophen and Febrile Seizure Recurrences During the Same Fever Episode. Pediatrics. November 2018, VOLUME 142 / ISSUE 5