[Etiology of contact urticaria with special reference to occupational substances].

On the basis of an extensive literature search (DIMI, MEDLINE-status at June 1992), the causes of contact urticaria so far known are displayed in tables. The contact urticariogens can be divided into (1) chemically defined substances and (2) chemically undefined biological materials. The causes most frequently encountered in 16 professions are given. Numerous agents are known for medical professions (physicians, nurses, dentists and dental technicians, veterinary surgeons). Today, the most frequent single cause of contact urticaria is probably the presence of latex proteins in rubber (gloves, condoms, tubes, balloons, etc.). When testing is performed a stepwise approach is recommended for safety reasons (rub test, prick test, scratch chamber test). For some contact urticariogens a commercial radioallergosorbent test (RAST) is available. In the cases reported in the literature it is not always possible to decide definitely whether the pathogenetic mechanism was immunologic (IgE mediated) or non-immunologic (toxic or pseudoallergic). When there is a high degree of sensitization (e.g. to latex) professional activities must be severely restricted, or even completely discontinued in rare cases.