[Skin tests in allergic vasculitis].

For etiologic checking of cutaneous vasculitis, skin testing may be of valuable help: epicutaneous patch-tests with delayed lecture (48 h.) performed with contact haptens (rubber allergens, azo dyes, resins ...) or drugs in pigmented progressive purpuric skin eruptions; prick-tests submitted to delayed (6-8 h.) clinic and histologic lecture, performed with miscellaneous drug or food-derived, microbial or environmental antigens in necrotizing vasculitis. In these conditions skin testing should be approached with great caution, because of the occurrence of non relevant positive reactions and the risk of precipitation of cutaneous or disseminated lesions of vasculitis.