DERMATITIS VENENATA DUE TO POTASSIUM UNDECYLENATE

We have recently seen a case of dermatitis venenata due to potassium undecylenate. We have been unable to find any previous report of dermatitis venenata due to undecylenic acid or its salts. In view of the widespread use of these substances in the local treatment of dermatophytosis, we feel that the possibility of one of these agents producing a contact dermatitis should be made known. REPORT OF A CASE J. B., a 52-year-old white man, had intermittent scaling and itching between the toes. He applied timofax® ointment (a cream containing 10% undecylenic acid as free acid and potassium salt) to the feet on two successive days, and on the third day the dorsa of the feet became erythematous, edematous, and exudative. Application of the ointment was discontinued, and there was gradual healing with soothing local therapy. There were slight residual erythema and fissuring at the base of the left