Some children have seizures or convulsions when they have fevers. Febrile seizures occur in 3% to 5% of otherwise healthy children between the ages of 6 months and 5 years. Toddlers are the most commonly affected.
The seizure begins with the sudden sustained contraction of muscles on both sides of a child’s body — usually the muscles of the face, the trunk, the arms and the legs. Often a haunting, involuntary cry or moan emerges from the child, from the force of the muscle contraction.
The child will fall, if standing, and may pass urine. He may vomit. He may bite his tongue. The child will not be breathing, and may begin to turn blue. Finally, the sustained contraction is broken by repeated brief moments of relaxation — the child’s body begins to jerk rhythmically.
Febrile seizures are brought on by the sudden stimulation of many brain cells at once. Experts argue over whether febrile seizures are triggered by the height of the fever or by the rate of rise. I suspect that both play a role.
Most febrile seizures occur well within the first 24 hours of an illness, not necessarily when the fever is highest. Often the seizure is the first sign of a fever, making febrile seizures hard to prevent.
A simple febrile seizure stops by itself within a few seconds to 10 minutes, sometimes followed by a brief period of drowsiness or confusion. Anticonvulsant medicines are generally not needed.
A complex febrile seizure is one that lasts longer than 15 minutes, occurs in an isolated part of the body, or recurs during the same illness.
During the seizure leave your child on the floor, although you may want to slide a blanket under him if the floor is hard. Move him only if he is in a dangerous location. Loosen any tight clothing, especially around the neck. If possible, open or remove clothes from the waist up. If he vomits, or if saliva and mucus build up in the mouth, turn him on his side or stomach.
Don’t try to restrain your child, or stop the seizure movements.
Don’t try to force anything into his mouth to prevent him from biting his tongue, as this increases the risk of injury.
Focus your attention on bringing the fever down. Inserting rectal acetaminophen (Tylenol) is a great first step — if you happen to have some.
Don’t try to give him anything by mouth.
Apply cool washcloths to the forehead and neck. Sponge the rest of his body with lukewarm (not cold) water. (Cold water or alcohol may make him shiver and make the fever worse).
After the seizure is over and your child is awake, give him the normal dose of ibuprofen (Motrin or Advil) or acetaminophen (Tylenol).
Children should see a doctor as soon as possible after their first febrile seizure. If the seizure ends quickly, drive him to an emergency room when it is over. If the seizure is lasting several minutes, call 911 to have an ambulance bring him to the hospital.
Most febrile seizures are brought on by fevers arising from viral upper respiratory infections, ear infections, or roseola. Meningitis causes less than 0.1% of febrile seizures but should always be considered, especially in children less than one year old or who still look ill when the fever drops.
About one third of the children who have had a febrile seizure will have another one with a subsequent fever (about 2/3 won’t). Of those who do, about half will have a third seizure.
Sometimes febrile seizures run in families. If there is a family history, if the first seizure happened before 12 months of age, or if the seizure happened with a fever of <102, a child is more likely to fall in the group that has more than one febrile seizure.
To prevent future febrile seizures, give acetaminophen (Tylenol) and/or ibuprofen (Motrin or Advil) at the first sign of a fever (you may want to keep acetaminophen suppositories on hand). Then sponge your child with lukewarm water. Also give him cool liquids to drink — both to lower the temperature and to keep him well hydrated.
There is no evidence that febrile seizures cause death, brain damage, epilepsy, mental retardation, a decrease in IQ, or learning difficulties.
A small number of children who have had a febrile seizure do go on to develop epilepsy, but not because of the febrile seizures.
Last reviewed: October 30, 2006