[Two cases of side effects of a fumaric acid ester--local therapy]

We report on two cases of adverse reactions to topical treatment with monoethyl fumarate. One patient suffering from atopic dermatitis reacted with contact dermatitis; the other, suffering from psoriasis, developed a generalized, partly pustulous exanthema as well as signs of systemic involvement, such as tachycardia and dyspnea. As the causative mechanism we suggest non-immunological contact urticaria syndrome.