Febrile seizure

Febrile seizure
Other names	Fever fit, febrile convulsion
An analog medical thermometer showing a temperature of 38.8 °C or 101.8 °F
Specialty	Emergency medicine, neurology
Symptoms	Tonic-clonic seizure[1]
Usual onset	Ages of 6 months to 5 years[1]
Duration	Typically less than 5 minutes[1]
Types	Simple, complex[1]
Causes	High body temperature[1]
Risk factors	Family history[1]
Differential diagnosis	Meningitis, metabolic disorders[1]
Treatment	Supportive care[1]
Medication	Benzodiazepines (rarely needed)[1]
Prognosis	Good[1]
Frequency	~5% of children[2]

A febrile seizure, also known as a fever fit or febrile convulsion, is a seizure associated with a high body temperature but without any serious underlying health issue.^[1] They most commonly occur in children between the ages of 6 months and 5 years.^[1][3] Most seizures are less than five minutes in duration, and the child is completely back to normal within an hour of the event.^[1][4] There are two types: simple febrile seizures and complex febrile seizures.^[1] Simple febrile seizures involve an otherwise healthy child who has at most one tonic-clonic seizure lasting less than 15 minutes in a 24-hour period.^[1] Complex febrile seizures have focal symptoms, last longer than 15 minutes, or occur more than once within 24 hours.^[5] About 80% are classified as simple febrile seizures.^[6]

Febrile seizures are triggered by fever, typically due to a viral infection.^[6] They may run in families.^[1] The underlying mechanism is not fully known, but it is thought to involve genetics, environmental factors, brain immaturity, and inflammatory mediators.^[7][8][6] The diagnosis involves verifying that there is not an infection of the brain, there are no metabolic problems, and there have not been prior seizures that have occurred without a fever.^[1][6] Blood testing, imaging of the brain, or an electroencephalogram (EEG) is typically not needed.^[1] Examination to determine the source of the fever is recommended.^[1][6] In otherwise healthy-looking children a lumbar puncture is not necessarily required.^[1]

Neither anti-seizure medication nor anti-fever medication are recommended in an effort to prevent further simple febrile seizures.^[1][9] In the few cases that last greater than 5 minutes, a benzodiazepine such as lorazepam or midazolam may be used.^[1][10] Efforts to rapidly cool during a seizure is not recommended.^[11]

Febrile seizures affect 2–10% of children.^[2] They are more common in boys than girls.^[12] After a single febrile seizure there is an approximately 35% chance of having another one during childhood.^[6] Outcomes are generally excellent with similar academic achievements to other children and no change in the risk of death for those with simple seizures.^[1] There is tentative evidence that affected children have a slightly increased risk of epilepsy at 2% compared to the general population.^[1]