In spring 1992, several farmers in the western part of The Netherlands developed dermatitis on their hands, forearms and face. In some, the legs, trunk and genitals were also affected. Complaints ranged from a mildly itchy, papular rash to a painful, weeping and blistering dermatitis. Medical aid was needed by 5/9 of them. Some of the farmers grew seed potatoes, the others cultivated lilies. All of them had in common that their complaints emerged after repeated application of a new fungicide over several weeks. The fungicide was Shirlan, with fluazinam as its active ingredient. 9 farmers were patch tested with a concentration range of the whole formulation (aq.) and of the active ingredient (pet.). In 7 of 9 farmers, positive patch tests were scored with both the whole formulation (down to 0.01% aq.) and fluazinam itself (down to 0.1% pet.). Patch tests in consecutive control patients (n = 10) were all negative. As it was impossible to substitute fluazinam as the active ingredient, farmers are now supplied with detailed information as to how to avoid skin contact as much as feasible.