Predictors of recurrent febrile seizures. A prospective cohort study.

OBJECTIVES: To define the risk and identify predictors of single and multiple recurrent febrile seizures.

METHODS: Children (n = 428) with first febrile seizures were prospectively identified and followed for 2 or more years. Parents were interviewed soon after their children's first febrile seizure and were called every 3 months to ascertain recurrent febrile seizures. Medical records of first and recurrent seizures were reviewed for additional information.

RESULTS: A total of 136 children (31.8%) experienced recurrent seizures: 73 (17.1%) had only 1 recurrence, 38 (8.9%) had 2 recurrences, and 25 (5.8%) had 3 or more recurrences. Young age at onset, a history of febrile seizures in a first-degree relative, low degree of fever while in the emergency department, and a brief duration between the onset of fever and the initial seizure were strong independent predictors of recurrent febrile seizures. With these 4 factors combined, it is possible to define groups of children having very high and very low probabilities of having any recurrences (> 70% vs < 20%), having 2 or more recurrences (> 60% vs < 10%), and having 3 or more recurrence (12% vs about 0%). In children who had at least 1 recurrence, age at the time of the first recurrence and a family history of epilepsy were predictors of subsequent recurrences.

CONCLUSIONS: In children who have had a first febrile seizure, recurrences are common. The risk for 1 or more recurrences can be meaningfully predicted at the time of the initial febrile seizure with a combination of the 4 factors identified in this study.