A febrile seizure is a seizure that occurs in children between six months and five years of age who are neurologically healthy. Common characteristics of simple febrile seizures include a short duration (less than 15 minutes), generalized quality, and occurring only once in a 24-hour period. Other types of febrile seizures can occur in children with a history of a previous afebrile seizure or those who have an abnormal neurologic history. Offringa and Moyer provide an evidence-based review of questions about the management of febrile seizures in children.

The first point to consider is identification of children with bacterial meningitis. In the United States, the prevalence of meningitis in children presenting with fever and seizures is between 1 and 2 percent. One study specifically looked at the relationship of symptoms and signs with meningitis in these children and provides statistical data. Major and minor clinical risk factors that are associated with meningitis are listed in the accompanying table. The child's age, gender, blood test results, and degree of fever had no diagnostic value for meningitis.

The second point concerns the utility of therapy with antiepileptic medication to decrease the likelihood of future febrile seizures. Several studies evaluating the efficacy and safety of phenobarbital, valproate, and diazepam for this purpose did not arrive at a clear conclusion. Treatment decisions continue to rely on balancing the risk-benefit ratios in specific children and the concerns of the child's family.

The third point is the use of intermittent antipyretic treatment to prevent future febrile seizures. The single study reviewed showed no usefulness for this approach.

The final point concerns the risk of recurrence of febrile and other seizures. Recurrent seizures may be more common among children with an immediate family history of febrile or other seizures, a relatively low temperature at the time of the first seizure, a partial initial febrile seizure, and young age (younger than 12 months) at first seizure. A complex seizure or a prolonged first seizure (lasting more than 15 minutes) is not associated with an increased incidence of recurrent seizures. Although this epidemiologic information is helpful in counseling parents, there are no studies looking at seizure prevention with antiepileptic medications after a first or second febrile seizure.

The authors conclude that lumbar puncture is not necessary in children with a first febrile seizure who are at low risk based on the absence of major or minor risk factors. In most children in the United States, the likelihood of recurrence is low, and daily or intermittent anticonvulsant or antipyretic treatment is rarely indicated. Parental anxiety should be managed with education. Rectal diazepam can be provided to treat a seizure recurrence lasting more than 15 minutes. Parents should also be instructed to position the child appropriately during a seizure recurrence to optimize breathing capacity.

editor's note: Febrile seizures are common events, with a recurrence rate around 20 percent. Parents are often unnecessarily fearful about the high likelihood of another febrile event. Educating parents about the benign nature of febrile seizures and discussing epidemiologic and preventive measures can reduce their anxiety. Recurrent febrile seizures increase the likelihood of additional episodes, and there is a correlation between the degree of fever during an infectious episode and the likelihood of febrile seizures. Prophylactic antipyretic therapy has no demonstrated efficacy in reducing recurrences, and intermittent use of benzodiazepines may be helpful in some children. Rectal diazepam has successfully prevented febrile seizures during episodes of fever in some children. Intranasal or buccal midazolam has recently been reported to be as effective as diazepam and has a better safety profile. Continuous antiepileptic medication use has excessive side effects.—r.s.