What are febrile seizures?

Photo of a man comforting a child who has a fever (PantherMedia / Suzanne Tucker)

Febrile seizures are most common in toddlers. Although they can be very alarming, they're usually not dangerous. Children are exhausted after a seizure but will usually recover within about an hour.

Febrile seizures may occur in children if their temperature rises quickly or if they have a very high temperature. During a febrile seizure, muscles in their body contract suddenly (“spasm”), they lose consciousness or don't respond to you. Their arms and legs may twitch and jerk, or their body may become unnaturally stiff and rigid. Sometimes their arms and legs relax quite suddenly again. Many children have dilated (big) pupils or a fixed gaze. Often their eyes roll back. Their lips or face may turn blue.

About 2 to 4 out of every 100 children will have had at least one febrile seizure before the age of five – usually between the ages of 12 to 18 months. Babies can already have febrile seizures at body temperatures as low as 38°C (100.4°F).  Febrile seizures don't affect the child's development. But it's still a good idea to have a doctor examine the child after they have had a febrile seizure.

What causes febrile seizures?

It's not exactly clear why some children tend to have febrile seizures and others don't. The tendency to have febrile seizures may run in families (be passed on from parents to children through their genes).

Although the symptoms of febrile seizures can be very alarming and worrying, they are only very rarely caused by a serious condition such as meningitis. Vaccines hardly play a role either. And febrile seizures aren't a sign of epilepsy.

What's the difference between simple and complex febrile seizures?

Simple febrile seizures usually don't last more than 3 to 4 minutes, and in rare cases up to 15 minutes. They don't occur again within the next 24 hours. Particularly the first time a child has a febrile seizure, it's important to call the emergency services and ask for an ambulance. That way the child can be examined immediately in order to rule out other causes. The emergency telephone number is 112 in Germany and many other European countries, and 911 in the U.S.

Complex febrile seizures last longer than 15 minutes. The muscle spasms usually only occur on one side of the body. The child may have a further seizure within the next 24 hours. If a child is having a complex febrile seizure of if the child is under three months old, it's important to call the emergency services and ask for an ambulance. The emergency doctor can then give the child anticonvulsant medication which normally stops the seizure soon after.

What can you do if a child has a febrile seizure?

Parents can help their child by

  • remaining as calm as possible themselves,
  • staying with the child and comforting them,
  • leaving the child in a lying position rather than holding them tight or shaking them,
  • preventing injury: Blankets and pillows can help to prevent the child from hurting themselves – for instance, if their arms and legs bump against the bed or wall;
  • laying the child on their side so that you can see their face clearly and saliva can flow out of their mouth.

It's also important not to give the child anything to eat or drink during a febrile seizure!

Can febrile seizures be prevented?

Up to 30 out of 100 children have another febrile seizure within 6 to 12 months of their first one.

Some parents are quick to give their child fever-reducing medication to try to prevent febrile seizures. But research suggests that fever-reducing medication can't prevent febrile seizures.