Henoch-Schönlein purpura mimicking acute appendicitis and Crohn's disease.

The typical Henoch-Schonlein syndrome, most commonly a disease of children, presents no difficulties in diagnosis with its characteristic rash, arthralgia, abdominal pain, and nephritis. However, with the absence or delayed appearance of one or more of these common features, the diagnosis may be missed, and some patients with predominantly abdominal involvement subjected to unnecesary laparotomy. The following case highlights the late appearance of a purpuric rash in an adult with acute abdominal pain, emphasizes the significance of microscopic haematuria, and illustrates the return of disturbed small-bowel X-ray appearances to normal.