ABSTRACT
Although well described in all age groups, Henoch-Schonlein purpura (HSP) is much less frequent in adults than in children. In school-aged children, the incidence of HSP is as high as 13.5 per 100,000. Girls and boys are affected equally and the median age of onset is 4 years (I). Controversy exists regarding seasonal increase in its occurrence with reports of peaks in the spring, fall, and winter months. In 50% of the children, HSP is preceded by an upper respiratory tract infection. Multiple organisms have been implicated in triggering HSP, including streptococci, Mycoplasma pneumoniae, Yersinia, Legionella, Helicobacter pylori, Epstein-Barr virus, hepatitis B, varicella, adenovirus, cytomegalovirus, and parvovirus B19. Several case reports link vaccinations against typhoid, paratyphoid A and B, measles, cholera, and yellow fever with the subsequent development of HSP. This suggests that more than one infectious agent may trigger the expression of the disease. In addition, allergens such as drugs (penicillin, ampicillin, erythromycin, lisinopril, enalapril, acetylsalicylic acid, quinine, and quinidine) as well as foods, exposure to cold, and insect bites have been implicated as potential triggers (2).
