Allergic contact dermatitis from pyoctanin.

Although pyoctanin is widely used in medicine, there are hardly any reports of contact allergy to it. Most reports of side-effects refer to irritant reactions after topical application. We describe 2 patients who developed pyoctanin contact dermatitis after long-term application on damaged skin. Positive patch test results down to concentrations of 0.0025% and 0.05% aqueous pyoctanin solution, respectively, were found.