Febrile Seizure

A febrile seizure is a seizure in a child aged 6 months to 5 years, with fever (38 °C or more), without central nervous system infection or other cause, and no prior afebrile seizure.

• It affects 2 to 5 percent of children and is the commonest seizure in childhood.
• Simple febrile seizures are generalised, last under 15 minutes, and do not recur within 24 hours.
• Complex febrile seizures are focal, last 15 minutes or more, or recur within 24 hours (or the same illness).
• Risk of recurrence is about 30 percent after a first seizure and higher if the first occurs before 12 months, a family history exists, or there is a low fever at onset.
• Risk of later epilepsy is 1 to 2 percent after simple, and 4 to 15 percent after complex seizures.
• Malaria is a common trigger in endemic regions.

The seizure usually occurs early in a febrile illness.

• Generalised tonic-clonic movements, or stiffening, with loss of consciousness.
• Typically lasts under 5 minutes, followed by a brief post-ictal drowsiness.
• Fever is often noticed only after the seizure.
• Child returns to normal alertness within an hour.
• Complex features: focal onset, prolonged duration, repeated seizures, or incomplete recovery.
• Examination identifies the source of fever (ear infection, tonsillitis, viral illness, malaria).
• Differential diagnosis: meningitis, encephalitis, cerebral malaria, epilepsy with fever provoking seizure, hypoglycaemia, electrolyte disturbance (hyponatraemia, hypocalcaemia), rigors, syncope, breath-holding spells and toxin ingestion.
• Complications: status epilepticus, aspiration, injury, recurrence, and anxiety in parents.

Diagnosis is clinical, with exclusion of serious causes.

• History: duration, type, family history, immunisation, development.
• Measure temperature, blood glucose and signs of meningism. Identify the focus of infection.
• Malaria test in all children in endemic areas.
• Lumbar puncture if meningeal signs, ill-appearance, or the child is under 12 months with incomplete immunisation or has taken prior antibiotics; consider in children aged 12 to 18 months.
• Blood tests (sodium, calcium, glucose) only if clinically indicated.
• Electroencephalography and neuroimaging are not routinely needed for simple febrile seizures. Consider them for complex seizures with persisting deficit or abnormal development.

Treat the seizure if it is ongoing, then treat the fever source.

• Supportive: place the child on the side, protect from injury, nothing in the mouth, give oxygen, check glucose and airway.
• Pharmacological, for a seizure lasting over 5 minutes: buccal midazolam 0.3 mg/kg (6 months to 1 year 2.5 mg; 1 to 4 years 5 mg; 5 to 9 years 7.5 mg), or rectal diazepam 0.5 mg/kg (maximum 10 mg), or intravenous lorazepam 0.1 mg/kg (maximum 4 mg) or intravenous diazepam 0.2 to 0.3 mg/kg. Repeat once after 5 to 10 minutes if the seizure continues.
• If the seizure persists beyond a second dose: this is status epilepticus: give intravenous phenytoin 20 mg/kg over 20 minutes, or levetiracetam 40 mg/kg over 10 minutes, or phenobarbital 20 mg/kg, and urgent senior care.
• Treat hypoglycaemia with 10 percent dextrose 2 to 5 mL/kg.
• Antipyretics: paracetamol 15 mg/kg every 6 hours for comfort. They do not prevent recurrence.
• Treat the source of infection (antimalarial, antibiotic as indicated).
• Prophylaxis: not routinely required. For prolonged or recurrent seizures, intermittent oral clobazam 0.5 to 1 mg/kg/day during fever (for 2 to 3 days), or home rescue buccal midazolam. Continuous antiepileptic drugs are not advised.
• Special groups: children with complex seizure, abnormal neurology, or under 12 months may need admission and observation. Parents need teaching on first aid.
• Red flags: seizure over 15 minutes, focal seizure, neck stiffness, bulging fontanelle, persistent drowsiness, rash, recurrent seizures in the same illness, and age under 6 months.
• Follow-up: reassure parents; recurrence is common but outcome is benign. Review if afebrile seizures occur.