[Retrospective analysis on 337 cases of 
Henoch-Schönlein purpura]

To determine differences in incidence, causes, clinical manifestation,prognosis between children and adults in patients with Henoch-Schönlein purpura (HSP).
 Methods: We retrospectively analyzed clinical data of 337 patients who hospitalized in the Department of Dermatology, Peace Hospital affiliated to Changzhi Medical College from Feb. 2013 to Jan. 2016. All patients were divided into two groups by age: a child group (patients were less than 14 years old) and an adult group (patients were more than or equal to 14 years old). The incidence, inducement, and recovery rates were compared between 2 groups.
 Results: There were 195 (57.86%) children and 142 (42.14%) adults in all subjects, and 143 (42.43%) were less than 10 years old. The incidence of HSP in children in autumn and winter was higher than that in adults (P<0.05). Children with upper respiratory infection outnumbered adults (P<0.01). Logistic analysis results showed that age more than 14 years old, gastrointestinal symptoms, skin purpura relapsed more than 3 times, and overexpression of anti-streptolysin O(ASO) were high risk factors for the HSP kidney damage (P<0.05). Increased white blood cell count, high percentage of neutrophil, and increased platelet count were independent risk factors for gastrointestinal symptoms (P<0.05). The curative rates for children were higher than those of adults (P<0.05) and curative rates of patients without kidney damage were higher than those in patients with kidney damage (P<0.05).
 Conclusion: HSP mainly occurs in children, especially in those under 10 years old. Compared with adult patients, children with HSP are easy to be induced by upper respiratory tract infection, with relatively mild renal damage and better prognosis.