Febrile seizures — Rapid | Doctor’s Passport

Synopsis

Classify fever-associated seizures by age and complexity, treat prolonged convulsions, detect central nervous system infection and give families clear recurrence and safety advice without unnecessary tests.

A febrile seizure is a fever-associated seizure in a child usually aged six months to five years without central nervous system infection, acute metabolic disturbance or previous afebrile seizures.
Simple means generalised, under 15 minutes and occurring once during the febrile illness; focal, longer than 15 minutes or recurrent in that illness makes it complex.
Do not wait 15 minutes to treat: any ongoing convulsive seizure at five minutes enters the paediatric status epilepticus pathway.
Search for the source of fever and assess meningitis or encephalitis on clinical features; the seizure label must never provide false reassurance about infection.
A well child who returns fully to baseline after a simple febrile seizure usually needs no routine EEG, neuroimaging or long-term antiseizure medicine.
Lumbar puncture is determined by infection suspicion, age, antibiotics already given and safety contraindications, not by a simple febrile seizure alone.
Antipyretics improve discomfort but do not reliably prevent another febrile seizure; never use cold sponging or undress a child excessively.
Teach parents to time future events, protect from hazards, avoid mouth insertion, use recovery position after jerking stops and call 999 at five minutes.
Complex events, atypical age, incomplete recovery or recurrent concerns need paediatric review and selected investigation.
Reassure accurately: simple febrile seizures do not damage the brain, and later epilepsy remains uncommon, while providing written return criteria.

Key red flags

Neck stiffness, bulging fontanelle, non-blanching rash, photophobia, persistent reduced consciousness or a toxic appearance suggests meningitis or encephalitis rather than an uncomplicated febrile seizure.

Focal onset, duration longer than 15 minutes or more than one seizure in the same febrile illness defines a complex phenotype needing paediatric assessment.

Age below six months or above five years is atypical for a febrile seizure and broadens infection, metabolic, structural and epilepsy differentials.

A seizure reaching five minutes needs rescue treatment even though the simple-versus-complex duration boundary is 15 minutes.

Persistent unilateral weakness, unequal pupils, raised intracranial-pressure signs or failure to return toward baseline requires urgent neurological investigation.

Poor perfusion, respiratory distress, hypoglycaemia, dehydration or suspected poisoning must be treated as concurrent emergencies rather than attributed to fever.

Investigation priorities

First-line clinical fever assessmentFirst stepFirst line

Identify infection source, sepsis risk, meningitis signs and whether the event meets simple criteria.

Management branches

Ongoing seizureTreat at five minutes

Convulsive activity persists to the emergency treatment threshold.

Use ABCDE, oxygen for hypoxaemia, monitoring and prompt glucose measurement.
Give one appropriate benzodiazepine dose and follow the timed paediatric status algorithm.
Investigate and treat sepsis, meningitis, encephalitis or metabolic disturbance in parallel.

Key medicines

Buccal midazolam rescueUse the child's prescribed plan; licensed age-banded single doses are 2.5 mg at 3–11 months, 5 mg at 1–4 years, 7.5 mg at 5–9 years and 10 mg from 10 years, with repeat dosing only under the emergency protocol.Call emergency services according to the plan, monitor breathing and recovery, avoid repeated unsupervised benzodiazepine doses and use an alternative route if buccal administration is unsafe.

Paracetamol for distressFor children aged 3 months to 11 years use the age- or weight-appropriate BNFc dose, commonly 15 mg/kg orally every 4–6 hours, no more than four doses in 24 hours and never duplicate paracetamol-containing products.Check formulation strength, weight, liver disease, malnutrition and previous doses; avoid therapeutic duplication and explain that a falling temperature does not exclude serious infection.

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