A febrile seizure is a convulsion that occurs in some children with a high temperature (fever). The vast majority of febrile seizures are not serious. Most occur with common illnesses such as ear infections and colds. Serious infections such as pneumonia, meningitis, etc, are less common causes. Full recovery with no permanent damage is usual. The main treatment is aimed at the illness that caused the fever.
What causes a febrile seizure and who has them?
A febrile seizure is sometimes called a febrile convulsion. Any illness that causes a fever (high temperature) can cause a febrile seizure. Most occur with common illnesses such as ear infections, coughs, colds, flu and other viral infections. Serious infections such as pneumonia, kidney infections, meningitis, etc, are less common causes.
About 3 in 100 children have a febrile seizure sometime before their sixth birthday. They most commonly occur between the ages of 18 months and three years. They are rare in children aged under six months and over the age of six years.
What does a febrile seizure look like?
Febrile seizures are classified into three types:
Simple febrile seizure: the most common type - occurs in about 15 in 20 cases
The child may look hot and flushed and their eyes may appear to roll backwards. They may appear dazed and then become unconscious. The body may go stiff, then generally twitch or shake (convulse). It does not usually last long. It may only be a few seconds and is unusual for it to last more than five minutes. The child may be sleepy for some minutes afterwards but within an hour or so the child will usually appear a lot better when their temperature has come down. Another feature of a simple febrile seizure is that it does not recur within 24 hours or within the same febrile illness.
Complex febrile seizure - occurs in about 4 in 20 cases
This is similar to a simple febrile seizure but has one or more of the following features:
- The seizure lasts more than 15 minutes and/or ...
- The seizure recurs within 24 hours or within the same febrile illness and/or ...
- The child is not fully recovered within one hour. This does not mean the seizure lasts more than an hour but that it takes more than an hour for the child to look and behave more like their normal self and/or ...
- The seizure has partial or focal features. This means that rather than a generalised twitch or shaking, only a part of the body may shake. For example, just one arm or just one leg.
Febrile status epilepticus - occurs in less than 1 in 20 cases
This means the febrile seizure lasts for longer than 30 minutes.
What first aid should I do for a febrile seizure?
- Note the time it started.
- Lie the child on their side with their head in line with the body or slightly lower (the recovery position).
- Do not put anything into their mouth or shake the child.
- When the seizure stops, try to lower the child's temperature to make them more comfortable. To do this, take off their clothes (if the room is warm). When the child has recovered enough to swallow, give a drink and some paracetamol or ibuprofen. In the past, common advice thought to help cooling was to sponge with lukewarm water but this is no longer thought to help so is not recommended.
- Stay with the child at night.
What should happen after immediate first aid?
Call an ambulance if a seizure lasts more than five minutes (this includes small twitching movements, even if large jerking movements have stopped).
You should also contact a doctor urgently or ring for an ambulance if:
- The child does not improve quickly once a short seizure is over.
- Another seizure starts soon after the first one stops.
- The child has difficulty breathing.
- The child was not fully conscious before the seizure or one hour afterwards.
- You suspect a serious illness is the cause of the fever. For example, if you suspect pneumonia or meningitis. See separate leaflet called 'Fever (High Temperature) in Children for details of symptoms to look out for.
No treatment is usually needed for the seizure itself if it stops within a few minutes. (However, treatment may be needed for the infection causing the fever.)
In all cases, the child should be seen by a doctor as soon as possible after a seizure for a check over to rule out serious illness.
Sometimes the seizure lasts longer and a doctor may give a medicine to stop it. For example, a doctor may put a medicine called diazepam into the rectum (back passage) or a medicine called midazolam into the side of the mouth. These medicines are absorbed quickly, directly into the bloodstream, from within the rectum or mouth, and stop a seizure. Sometimes the parents of children who are prone to recurrent febrile seizures are taught how to use one of these medicines. They are then given a supply to have in case a further febrile seizure occurs.
Is a febrile seizure dangerous?
Although alarming, a febrile seizure in itself is not usually dangerous. Full recovery is usual. Most illnesses which cause fever and febrile convulsions are the common coughs, colds and viral infections which are not usually serious. However, the illness that causes the fever is sometimes serious - for example, pneumonia or meningitis.
Can febrile seizures be prevented?
It may seem logical that if you keep a child's temperature down during a feverish illness it may prevent a febrile seizure. However, there is little scientific evidence to prove that this is so. (It is unclear what triggers the seizure. It is possibly some body chemical that is released during certain feverish illnesses rather than the temperature itself. Most children with a high temperature do not have a seizure.) However, it is common practice to keep a child cool when they have a feverish illness. This will make them feel more comfortable. Therefore, if a child appears hot, then the following will help to reduce the temperature:
- Keep the child very lightly dressed, or take all their clothes off if the room is warm.
- Give paracetamol (for example, Calpol®, Disprol®, etc) or ibuprofen.
- Give lots of cool drinks.
Will it happen again?
Only one seizure occurs in most cases. In about 3 in 10 children who have a febrile seizure, a second seizure occurs with a future feverish illness. In less than 1 in 10 children who have a febrile seizure, three or more further seizures occur during future feverish illnesses. A future febrile seizure is more likely if the first occurs in a child younger than 15 months, or if there is a family history of febrile seizures in close relatives (father, mother, sister, brother). Once the child is past three years old, the chance of a recurrence (getting more than one seizure) becomes much less likely. Therefore, recurrences are not common but it is best to be prepared. For example, practise putting your child into the recovery position.
Does a febrile seizure cause any permanent damage?
Usually not. Full recovery is usual with no after-effects. (Sometimes the infection causing the seizure causes complications but the seizure itself does not usually cause any damage.) Rarely, a seizure which lasts 30 minutes or more may cause some injury to the brain.
One study that followed children who had a febrile seizure found that "children who had febrile seizures did at least as well as, if not better than, children without febrile seizures on measures of intelligence, academic achievement, behaviour and working memory".
Is a febrile seizure a type of epilepsy?
No. Febrile seizures and epilepsy are two different conditions.
- The cause of a febrile seizure is related to the feverish illness and is not due to epilepsy or any brain abnormality.
- Epilepsy causes seizures without a fever. There is a separate set of leaflets that explain epilepsy in more detail.
Some parents wonder whether a febrile seizure in a child will lead on to the child developing epilepsy. About 2 in 100 children who have a febrile seizure develop epilepsy in later childhood. This is very slightly higher than the chance of epilepsy developing in children who have not had a febrile seizure. But this is probably because a small number of children are prone to develop both epilepsy and febrile seizures. So, having a febrile seizure does not cause epilepsy to develop.
Should a child who has had a febrile seizure have immunisations?
Yes. Some children develop a fever following immunisation. A very small number of children develop a febrile seizure following an immunisation. However, this is very unlikely to cause any permanent harm, or to happen again after a future immunisation.
Further reading & references
- Feverish illness in children - Assessment and initial management in children younger than 5 years, NICE Clinical Guideline (2007)
- Febrile seizure, Prodigy (June 2008)
- Sadleir LG, Scheffer IE; Febrile seizures. BMJ. 2007 Feb 10;334(7588):307-11.
- Jones T, Jacobsen SJ; Childhood febrile seizures: overview and implications. Int J Med Sci. 2007 Apr 7;4(2):110-4.
- Tosun A, Koturoglu G, Serdaroglu G, et al; Ratios of nine risk factors in children with recurrent febrile seizures. Pediatr Neurol. 2010 Sep;43(3):177-82.
|Original Author: Dr Tim Kenny||Current Version: Dr Laurence Knott||Peer Reviewer: Dr Tim Kenny|
|Last Checked: 18/11/2011||Document ID: 4246 Version: 39||© EMIS|
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