Purpuric allergic contact dermatitis to paraphenylenediamine.

A 59-year-old saleswoman of black hats presented with a severe purpuric eruption of the exposed areas of the face, neck and arms. Patch testing to paraphenylenediamine produced a purpuric test reaction. Similar eruptions have been reported due to N-isopropyl-N-phenylparaphenylenediamine (IPPD), a rubber antioxidant. The patient had previous dermatitis underneath the elastic portions of her undergarments. It was determined that IPPD is added to elastic material used in some elastic trim on undergarments in the United States. This relationship is discussed.