A simple febrile seizure is defined as a brief, generalized seizure that occurs once in a 24-hour period as a result of a fever and not an intracranial infection or other severe metabolic condition. Two adverse outcomes of febrile seizure are of concern: recurrence and the potential development of afebrile seizures, including epilepsy. The probability of recurrence is 30 to 50 percent, depending on the child's age at the first episode. The risk of epilepsy is only slightly increased in these children compared with the general population. The risk is slightly higher (2.4 percent) in children who had their first seizure within the first year of life and who subsequently have had multiple episodes. Even though febrile seizures are common, consensus about treatment is lacking. The Committee on Quality Improvement of the American Academy of Pediatrics has developed a practice parameter to help physicians treat febrile seizures.
Treatment of febrile seizures traditionally consists of continuous or intermittent therapy with anticonvulsants or no therapy. Anticonvulsants have not been proved to prevent subsequent development of afebrile seizures nor is there any evidence that febrile seizures cause structural or cognitive damage. Consequently, the risks and benefits of any therapy must be considered and compared with the effect of no treatment.
In developing this practice parameter, more than 300 medical journal articles reporting studies of febrile seizures and treatments were reviewed and, of these, 62 articles were abstracted. The effectiveness of phenobarbital, valproic acid, carbamazepine and phenytoin was reviewed. Carbamazepine and phenytoin have not been shown to prevent recurrence, whereas phenobarbital reduced the incidence of febrile seizures from 25 per 100 children to five per 100 children. However, hyperactivity and hypersensitivity reactions can occur with this drug. Valproic acid is considered as effective as phenobarbital in preventing recurrence but is associated with several potentially serious adverse effects, such as thrombocytopenia, weight changes and fatal hepatotoxicity. Intermittent treatment may include diazepam, which is associated with a 44 percent reduction in risk per patient year. However, its sedative effects can obscure signs and symptoms of a developing central nervous system infection. Antipyretics have also been used to prevent recurrence, but studies show that they do not have this effect.
The American Academy of Pediatrics concludes that a single episode of febrile seizure in young children is a common, benign event after which there is an excellent prognosis for recovery. Therefore, education and emotional support for patients and parents are recommended rather than medication. Parental anxiety associated with febrile seizures might be a reason to recommend intermittent oral diazepam at the onset of fever in a child with a history of febrile seizures. In other effective medications, the side effects are too many to be commensurate with the benefits.