ALLERGIC PATCH TEST REACTIONS CAUSED BY THE RUBBER CHEMICAL CYCLOHEXYL THIOPHTHALIMIDE

Rubber chemicals are among the most common occupational contact sensit izers. The most common rubber sensitizers are thiurams, thiazoles, car bamates and paraphenylenediamine derivatives. Here we present data on a less-well-known rubber chemical, N-(cyclohexylthio)phthalimide (CTP; CAS 17796-82-6). This chemical is currently the most widely used vulc anization retarder, but data on allergic contact dermatitis caused by CTP are lacking. We conducted a survey of 310 patients who had been pa tch tested with 30 rubber chemicals including CTP. 11 (3.5%) showed an allergic patch test reaction provoked by CTP, and 9.0% by thiurams. 4 of the patients reacted only to CTP and not to other rubber chemicals , whereas the other 7 concomitantly reacted to other rubber chemicals. After analyzing the patch test data of these 11 patients, it was conc luded that CTP probably did not cross-react with the other rubber chem icals. Therefore the patch test results may indicate independent sensi tization to CTP and other rubber chemicals. Because very little data o n the components of rubber chemicals in rubber products are available, the source of the putative sensitization to the rubber vulcanization retarder CTP is unknown. (C) Munksgaard, 1996.