A nationwide survey on epidemiological characteristics of childhood Henoch–Schönlein purpura in Taiwan

Abstract
Objective. To evaluate the annual incidence and other epidemiological characteristics of Henoch–Schönlein purpura (HSP) among children in Taiwan. Methods. The records of patients were derived from the research database of the Bureau of National Health Insurance, Taiwan, Republic of China, from January 1999 to December 2002. Children younger than 17 yr of age with the diagnosis of HSP were included into this study. Data for each patient including sex, age, date of onset and length of hospitalization were recorded and analysed. Results. A total of 2759 cases were included with an annual incidence of 12.9 (11.8–13.4) per 100 000 children P = 0.04), and had a lower incidence than females at older ages (P = 0.02). Disease onset was more common in autumn and winter, and no apparent change in seasonal pattern was noted over 4 yr. Conclusions. Insurance claim data provide useful information on the epidemiology of HSP in Taiwan. Childhood HSP in Taiwan, with an incidence of 12.9 per 100 000 children, occurs commonly in autumn and winter; and at the age of 5 to 6 yr. The characteristics presented in this study may provide valuable data for understanding and further studies of HSP.