[Multiple contact sensitization].

Contact allergy to several non-related haptens, usually termed polysensitization (PS), is often used to characterize patients who are particularly prone to sensitization. A conventional definition for PS is positive reactions to three or more haptens of the baseline series, e.g., the baseline series of the German Contact Dermatitis Research Group. Previous genetic as well as epidemiological studies have already indicated a number of potential risk factors for PS. In this context, both endogenous as well as exogenousfactors appear to be crucial. The former comprise polymorphism of IL-16 and TNF coding genes, the latter mostly occupational exposure, which often entails intense and repeated skin contact to a set of more or less characteristic contact allergens. Moreover, age and sex are related both with contact allergy to certain substances and with PS, as is the anatomical site of contact dermatitis. The degree to which contact allergy to a specific hapten is associated with PS, i.e., with contact allergy to several other haptens, varies greatly.