What is a Fever Seizure?

A fever seizure, or febrile seizure, is triggered by high fever in infants and young children. Children of up to 5 years of age might experience a fever seizure, but they are most common among those younger than 2 years old. During a seizure, the child might stiffen or twitch, the child’s eyes might roll back, and vomiting is possible. Parents often find seizures terrifying and distressing, but they typically are harmless.

High fever is responsible for triggering a fever seizure. Children with fevers of more than 102 degrees Fahrenheit (38.9 degrees Celsius) might experience a fever seizure. Typically, seizures occur during the first 24 hours of illness. Seizures usually are quite brief and might last between 10 seconds and 10 minutes. Complex seizures, in which multiple seizures take place in succession, also are possible, and these might go on for 15 minutes or more.

Fever seizures affect approximately 4 percent of all children, and of these, about 30 percent will experience multiple seizures before eventually outgrowing them. Approximately 25 percent of children who have fever seizures have a direct relative who also experienced childhood fever seizures. Seizures typically occur to children between 6 months and 3 years old, and they are most common among children who are 12–18 months old.

During a fever seizure, the child should not be moved unless the immediate area is dangerous, and when possible, it is safer for the area the be cleared of dangerous objects. Restrictive clothing or blankets can be loosened if needed, and if the child vomits or if mucus or saliva pools in the mouth, it might be necessary to turn the child onto his or her side or stomach. The child is in no danger of swallowing his or her tongue during a fever seizure, and any attempts to place objects in the mouth or to restrain the child generally serve only to make injury more likely.

Many parents are concerned about potential harm during fever seizures, such as brain damage or epilepsy. Children who experience fever seizures are no more likely to be diagnosed with epilepsy or any other disorder. Some children who develop epilepsy will, however, experience fever seizures before displaying symptoms of epilepsy, but there has been no proof of a cause-and-effect relationship.

Fever seizures typically are harmless, but the associated fever might be cause for serious concern. Fevers that trigger seizures are often caused by ear or respiratory infection and require an antibiotic for treatment. A high fever is also a symptom of meningitis, which can be quite serious. Any child with a fever high enough to trigger seizures should be seen by a medical professional.