A 4-year-old with a first febrile seizure and a family history of epilepsy

This is a simple febrile seizure.

Criteria for a simple febrile seizure:

• Generalised (not focal) - met.
• Duration less than 15 minutes - met (3 minutes).
• Only one seizure in 24 hours - met (no previous seizures, and none since).
• Age 6 months to 5 years - met (4 years).
• No evidence of intracranial infection or metabolic cause - met on examination.

Features that would have made it complex:

• Focal onset or focal features (e.g. eye deviation, unilateral jerking, Todd's paresis).
• Duration greater than 15 minutes, or recurrent seizures within 24 hours.
• Age under 6 months (would raise concern for a different cause, including meningitis or metabolic disease).
• Post-ictal focal deficit or prolonged post-ictal state.
• Signs of meningitis/encephalitis - neck stiffness, bulging fontanelle, non-blanching rash, persistent altered consciousness.

Important nuance: the family history of epilepsy in the brother and febrile seizures in the father does not change the classification of this episode, but it does raise the baseline risk of future febrile seizures and, to a lesser extent, of later epilepsy. It should not change acute management.

Lumbar puncture - not routinely indicated.

• She is 4 years old, has had a generalised seizure, is rousable, has no meningism, no rash, and no focal signs. The current guidance (and the NICE/ AAP approach) is that LP is not required in a child with a simple febrile seizure who has no clinical signs of meningitis.
• LP would be indicated if there were meningism, a non-blanching rash, prolonged altered consciousness, focal neurology, or if the child were under 12 months (where signs are unreliable).
• If antibiotics have been given before presentation, the threshold for LP lowers because signs may be masked.

Blood tests - not routinely indicated.

• Glucose, electrolytes, calcium, and magnesium do not need to be checked in a well-looking child with a simple febrile seizure; abnormalities are rare and do not change management.
• Blood tests would be indicated if there were dehydration, prolonged seizure, recurrent seizures, or a suspected metabolic cause.

Neuroimaging - not indicated.

• CT or MRI is not indicated after a simple febrile seizure with a normal neurological examination.
• Neuroimaging would be considered for focal seizures, focal neurological signs, a prolonged or recurrent seizure, or if there is a suspicion of raised intracranial pressure.

What should be done:

• Treat the fever with paracetamol 15 mg/kg (240 mg) and encourage fluids; antipyretics do not prevent recurrence but improve comfort.
• Examine for the source of fever (ears, throat, chest, urine) - the coryzal illness is the likely source.
• Safety-net: parents should be taught what to do if she seizes again (recovery position, time the seizure, call an ambulance if >5 minutes).
• Consider rectal diazepam or buccal midazolam for home use only if there is a history of prolonged seizures - not indicated for a first simple febrile seizure.

Recurrence of febrile seizures:

• About 30–35% of children have at least one further febrile seizure. Risk is higher if the first seizure occurred under 18 months, if there is a family history of febrile seizures, and if the fever was relatively low at the time of the seizure.
• This child is 4 years old and has a family history, so her risk is at the lower end of that range - most children who have a first febrile seizure at 4 will not have another.
• Recurrence does not mean brain damage; simple febrile seizures are not associated with cognitive decline, and most children outgrow them by age 5–6.

Risk of later epilepsy:

• The baseline population risk of epilepsy is about 1%. After a simple febrile seizure it rises to about 2–3%.
• The risk is higher with complex features (focal, prolonged, recurrent), pre-existing developmental delay, or a family history of epilepsy. This child has a brother with epilepsy, which modestly raises her risk, but her normal development and simple seizure keep the absolute risk low.
• Be honest: "There is a small increase in the chance of epilepsy later, but the great majority of children with a febrile seizure do not develop epilepsy."

What to tell them to do:

• Do not give prophylactic anticonvulsants (continuous or intermittent) for simple febrile seizures - the risks outweigh the benefits, and they do not prevent epilepsy.
• Do treat fever for comfort with paracetamol or ibuprofen, but explain that this does not prevent seizures.
• Do teach first aid: place the child on her side, do not put anything in her mouth, time the seizure, and call an ambulance if it lasts more than 5 minutes.
• Do seek review if she has a seizure without fever, a focal seizure, or a prolonged seizure.
• Reassure them that the 3-minute duration was not dangerous and that she is now back to herself.
• Offer written information and a follow-up appointment with the GP or paediatrician.