Dermatitis in a rubber tyre factory

An outbreak of occupational dermatitis in a rubber tyre factory is reported. An unusual clinical picture was recognized. Patch tests revealed a high sensitization rate to the MBT derivative used: 2-(2′-4′dinitrophenylthio) benzothiazole. Since tests with MBT mix and dinitrophenol were negative, sensitization to a contaminant was suspected. DNCB was traced as the substance responsible.