Contact sensitivity to Irgasan DP 300

Two persons had allergic contact dermatitis caused by Irgasan 0.2 % in a deodorant foot‐powder and 0.12 % in a deodorant stick respectively. Both had positive patch test reactions to Irgasan 2 % pet. One patient was further tested with Irgasan 1 % pet, and 0.5 % pet. She had positive reactions to these dilutions. In a blind half‐sided usage test, a soap bar containing 0.5 % Irgasan caused mild itching and a perceptible erythema, although the use of this soap was otherwise tolerated for one month. The soap bar without Irgasan caused no reactions. Although primary sensitization from Irgasan toilet soaps has not been reported, a previously sensitized person may react to the use of Irgasan in soaps.