Allergic contact dermatitis to underwear elastic. Chemically transformed by laundry bleach.

Six subjects, allergic to the elastic in their undergarments, were patch test-negative to the rubber components and new elastic from the suppliers. However, washing the rubber with sodium hypochlorite gave the subjects allergic responses due to the effect of bleach on the rubber accelerator, zinc dibenzyldithiocarbamate (ZDC). To identify the allergen, ZDC was reacted with the sodium hypochlorite, and the resultant gum was extracted with diethyl ether. Eight compounds were identified in the reaction mixture by gas chromatography-mass spectrometry. The individual components were tested on volunteers after sensitization to the reaction mixture was produced in 14 of 25 volunteers. One component, N,N-dibenzylcarbamyl chloride produced an allergic response in each sensitized volunteer.