The syndrome is usually seen in children, but people of any age may be affected. It is more common in boys than in girls. Many people with Henoch-Schonlein purpura had an upper respiratory illness in the previous weeks.
Update Date 4/20/2013
Updated by: Gordon A. Starkebaum, MD, Professor of Medicine, Division of Rheumatology, University of Washington School of Medicine. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.