Allergic contact dermatitis from 3-iodo-2-propynyl-butylcarbamate (IPBC) - an update.

Results from 3 1/2 years of routine patch testing with 3-iodo-2-propynyl-butylcarbamate (IPBC) are presented. From 1996 to 1999, a total of 3168 persons (2093 women and 1075 men) were patch tested with IPBC, and 7 cases were found to be positive. In 2 cases, sensitization could be attributed to cosmetics, and in a further 2 cases cosmetics were the most likely cause of sensitisation. It is concluded that the use of IPBC in cosmetic products can lead to contact sensitization and allergic contact dermatitis. 2 of the 7 reported cases with IPBC allergy were also found positive to thiuram, and possible cross-reactivity between IPBC and thiuram is discussed.