Dermatitis from shoes and an amputation prosthesis due to mercapto‐benzthiazole and paratertiary butyl formaldehyde resin

It was found that the contact surface of the leather on the prosthesis was impregnated with PTBP formaldehyde resin. A patch test with the other surface of the leather was negative. The formaldehyde test was negative. The patient had no atopic history, but his lgE was high (380 IUfml). Contact sensitivity to the prosthesis in amputees is rarely reported. In a series of seven cases van Ketel (1977) found the allergen to be chromate (2), hexomedine (2), chamois leather (1), paraphenylenediamine (1) and paratertiary butyl phenol formaldehyde (1). Our patient had a double sensitivity, to footwear and to an amputation prosthesis, with two allergens: mercaptobenzthiazole and PTBP resin. The sensitizations had developed independently, that on the amputation stump being the most recent. The cause of the latter was most likely the PTBP resin since the prosthesis contained no rubber, but both allergens were probably responsible for the foot dermatitis (Malten 1958).