A prospective incidence study of febrile convulsions.

A prospective epidemiological study of febrile convulsions (FC) was performed during a 20-month period. 128 children with FCs were identified. The annual first attendance rate and annual incidence rate were 500/100,000 and 460/100,000 respectively, in the age group 0-4 years. The cumulative incidence was 4.1%. FCs were more common among boys, with a male to female ratio of 1.72 to 1. The median and mean age for first FC was for boys 16 and 19.9 months respectively, and for girls 18 and 19.7 months respectively. During an average follow-up period of 20 months, 18% had another FC and 10% had two or more FCs. 8.6% had an initial complicated FC. Four children had FCs within two weeks after being vaccinated by combined vaccine against morbilli, rubella and parotitis. Three of these had earlier had an FC.