[Leg ulcer and allergic eczematous contact dermatitis incidence of contact allergies induced by topical therapy (author's transl)].

In the IInd Department of Dermatology, Vienna University, 200 patients (143 female, 57 male) suffering from leg ulcers due to chronic venous insufficiency underwent patch testing with routine allergens, vehicles and their ingredients, as well as topical antibiotics. 114 patients (57%) had contact allergy. Balsam of Peru heads the list of allergens with postive reactions in 22%, closely followed by oil/water emulsions such as Drointin (21%), Ultrasicc (20%) and Ung. emulsificans aqu. (15,5%). The causative agents in these preparations were emulsifiers on the one hand (Lanette O, E, N) and preservatives (parabens) on the other hand. In comparison, allergic reactions to water/oil emulsions were less common. The low index of sensitivity to local antibiotics was also surprising. The results of the present study, in accordance with other reports in the literature, underline the need (1) for full label diclosure of cosmetics and topically-applied drugs and (2) for patch-testing every patient suffering from leg ulcers of long duration.