Symptoms:

A febrile seizure may be as mild as the child's eyes rolling or limbs stiffening. Often a fever triggers a full-blown convulsion that involves the whole body.

Febrile seizures may begin with the sudden contraction of muscles on both sides of a child's body -- usually the muscles of the face, trunk, arms, and legs. The child may cry or moan from the force of the muscle contraction. The contraction continues for several seconds, or tens of seconds. The child will fall, if standing, and may pass urine.

The child may vomit or bite the tongue. Sometimes children do not breathe, and may begin to turn blue.

Finally, the contraction is broken by brief moments of relaxation. The child's body begins to jerk rhythmically. The child does not respond to the parent's voice.

A simple febrile seizure stops by itself within a few seconds to 10 minutes. It is usually followed by a brief period of drowsiness or confusion. A complex febrile seizure lasts longer than 15 minutes, is in just one part of the body, or occurs again during the same illness.

Febrile seizures are different than tremors or disorientation that can also occur with fevers. The movements are the same as in a grand mal seizure.

Signs and tests:

The health care provider may diagnose febrile seizure if the child has a grand mal seizure but does not have a history of seizure disorders (epilepsy). In infants and young children, it is important to rule out other causes of a first-time seizure, especially meningitis.

In a typical febrile seizure, the examination usually shows no abnormalities other than the illness causing the fever. Typically, the child will not need a full seizure workup (which includes an EEG, head CT, and lumbar puncture (spinal tap)).

To avoid having to undergo a seizure workup:

• The child must be developmentally normal.
• The child must have had a generalized seizure, meaning that the seizure was in more than one part of the child's body, and not confined to one part of the body.
• The seizure must not have lasted longer than 15 minutes.
• The child must not have had more than one febrile seizure in 24 hours.
• The child must have a normal neurologic exam performed by a health care provider.