An epidemiologic study of headache among children and adolescents of southern Brazil.

To study the epidemiology of pediatric headache, we conducted a cross-sectional study of a randomized and proportional sample of 538 male and female students, 10 to 18 years old. They were in the 5th to 8th grade of the schools of Porto Alegre, RS, Brazil. The headache disorders were classified on the basis of clinical interview as well as a physical and neurological examination using the operational diagnostic criteria of the International Headache Society (IHS). The following headache prevalences were found: lifetime, 93.2%; last year, 82.9%; last week, 31.4%; last 24 h, 8.9%. Last week and last 24 h headache complaints were twice as prevalent in the female group. During the last year the prevalence of headache disorders was 72.8% for tension-type and 9.9% for migraine headache and was not associated with age distribution. Only the last year and last week prevalences of tension-type headache were significantly higher in the female group. The last year prevalence of headache disorders proved to be positively associated with sex and age variables. The prevalence of headache disorders was found to be extremely high in this population group, requiring more attention on the part of investigators as a public health problem.