To the Editor.— We would like to report a case of contact dermatitis due to perfume in Mycolog cream. Report of a Case.— A 63-year-old white man was examined on April 1, 1974, because of a nummular, eczematous eruption involving his trunk and extremities. He had first become aware of an eruption three months previously. He had treated it with Mycolog cream and it had become worse. He was treated with orally administered prednisone and topically applied triamcinolone acetonide cream, and after four weeks, the eczematous eruption resolved. However, he then had psoriasis in the areas that had been eczematous. A retrospective diagnosis was made of contact dermatitis due to Mycolog cream, which had been topically applied to preexisting areas of psoriasis. The patient was patch tested on June 10, 1974, to 0.1% aqueous thimerosal (Mycolog cream base), 20% aqueous neomycin sulfate (Myciguent Cream), 10% aqueous gramicidin (Mycolog cream), 0.1%