Febrile Convulsions

What are febrile convulsions?
Febrile convulsions are triggered by high fever in infants or small children. Most febrile convulsions last 1-2 minutes, although some can be as brief as a few seconds while others last for more than 15 minutes.

During a convulsion, your child may:
become stiff
become unconscious or not know where they are
have jerking or twitching movements
have the eyes roll backward
have noisy breathing
after the seizure, your child may be sleepy and confused for a while.

Children who have febrile convulsions are usually 6 months to 5 years old. Most child's first febrile convulsion usually occurs before 3 years of age.

The majority of children with febrile convulsions have rectal temperatures greater than 102 degrees F. Most febrile convulsions occur during the first day of a child's fever.

How frequent are febrile convulsions?
Approximately one in every 25 children will have at least one febrile convulsion, and more than one-third of these children will have additional febrile convulsions before they outgrow the tendency to have them.

What are risk factors for a child to have recurrent febrile convulsions?
A few factors appear to increase a child's risk of having recurrent febrile convulsions, including young age (less than 15 months) during the first convulsion, frequent fevers, and having immediate family members with a history of febrile convulsions. If the convulsion occurs soon after a fever has begun or when the temperature is relatively low.

Are febrile convulsions harmful?
Although febrile convulsions can be frightening to parents, the majority of them are harmless. During a convulsion, there is a small chance that the child may be injured by falling or may choke from food or saliva in the mouth. Using proper first aid for convulsions can help avoid these hazards.

There is no evidence that febrile convulsions cause brain damage. Large studies have found that children with febrile convulsions have normal school achievement and perform as well on intellectual tests as their siblings who don't have convulsions. Even in the rare instances of very prolonged convulsions (more than 1 hour), most children recover completely.

However, although the absolute risk remains very small, certain children, who have febrile convulsions, have an increased risk of developing epilepsy, which is characterized by recurrent convulsions that are not triggered by fever. These children with the history of febrile convulsions, who later develop epilepsy, are with longer duration for the convulsion, affecting only part of the body, or recurring within 24 hours, and other neurological abnormalities.

What should be done for a child having a febrile convulsion?
Parents should stay calm and carefully observe the child. To prevent accidental injury, the child should be placed on a protected surface such as the floor or ground. The child should not be held or restrained during a convulsion. To prevent choking, the child should be placed on his or her side or stomach. When possible, the parent should gently remove all objects in the child's mouth. The parent should never place anything in the child's mouth during a convulsion. Objects placed in the mouth can be broken and obstruct the child's airway.

Bringing your child's fever down as quickly as possible may shorten the seizure. Remove your child's clothing and apply cold washcloths to the face and neck. If the seizure persists, sponge the rest of the body with cool water. As the water evaporates, your child's temperature will fall.
If the convulsion lasts longer than 10 minutes, the child should be taken immediately to the nearest medical facility for further treatment. Once the convulsion has ended, the child should be taken to his or her doctor to check for the source of the fever. This is especially urgent if the child shows symptoms of stiff neck, extreme lethargy, or abundant vomiting.

How are febrile convulsions diagnosed and treated?
Febrile convulsion is diagnosed by the history. Before the diagnosing, doctors sometimes perform tests to be sure that convulsions are not caused by something other than simply the fever itself. For example, if a doctor suspects the child has meningitis (an infection of the membranes surrounding the brain), a spinal tap may be needed to check for signs of the infection in the cerebrospinal fluid (fluid that bathes the brain and spinal cord). Also, doctors often perform other tests such as examining the blood and urine to pinpoint the cause of the child's fever.

A child who has a febrile convulsion usually doesn't need to be hospitalized. If the convulsion is prolonged or is accompanied by a serious infection, or if the source of the infection cannot be determined, a doctor may recommend that the child be hospitalized for observation.

How are febrile convulsions prevented?
If a child has a fever most parents will use fever-lowering drugs such as acetominophen or ibuprofen to make the child more comfortable, although there are no studies that prove that this will reduce the risk of a convulsion. One preventive measure would be to try to reduce the number of febrile illnesses, although this is often not a practical possibility.

Prolonged daily use of oral anticonvulsants, such as phenobarbital or valproate, to prevent febrile convulsions is usually not recommended because of their potential for side effects and questionable effectiveness for preventing such convulsions.

Children especially prone to febrile convulsions may be treated with the drug diazepam orally or rectally, whenever they have a fever. The majority of children with febrile convulsions do not need to be treated with medication, but in some cases a doctor may decide that medicine given only while the child has a fever may be the best alternative. This medication may lower the risk of having another febrile convulsion. It is usually well tolerated, although it occasionally can cause drowsiness, a lack of coordination, or hyperactivity. Children vary widely in their susceptibility to such side effects.

When should I call my child's health care provider?
Call your doctor's office IMMEDIATELY after the seizure is over.