title: 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 <17 yr of age. The occurrence of HSP had a peak at the age of 5 to 6 yr. In this study, 1118 (40.5%) patients had been hospitalized at some stage. There were 1454 males and 1305 females, for a male to female ratio of 1.11. Males had a higher annual incidence before the age of 10 yr (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.
authors.affiliation: Department of Pediatrics, National Taiwan University Hospital, College of Medicine, National Taiwan University, No 7 Chung-Shan South Road, Taipei, Taiwan.
authors.forename: Y-H
authors.initials: YH
authors.lastname: Yang
authors.forename: C-F
authors.initials: CF
authors.lastname: Hung
authors.forename: C-R
authors.initials: CR
authors.lastname: Hsu
authors.forename: L-C
authors.initials: LC
authors.lastname: Wang
authors.forename: Y-H
authors.initials: YH
authors.lastname: Chuang
authors.forename: Y-T
authors.initials: YT
authors.lastname: Lin
authors.forename: B-L
authors.initials: BL
authors.lastname: Chiang
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D002648:Child; D002675:Child, Preschool; D016208:Databases, Factual; D005260:Female; D006306:Health Surveys; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D011695:IgA Vasculitis / Q000453:epidemiology*; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009313:National Health Programs / Q000706:statistics & numerical data; D012621:Seasons; D017678:Sex Distribution; D013624:Taiwan / Q000453:epidemiology