Irritant dermatitis from tri-butyl tin oxide and contact allergy from chlorocresol.

A shipwright developed a delayed bullous irritant dermatitis from contact with a bis-tri-butyl tin oxide (TBTO) containing antifouling paint. He subsequently developed sensitization to 4-chloro-m-cresol, a constituent of a steroid cream. No cross sensitivity lo 4-ehloro-3,5 xylenol was seen. Low concentrations of 4-chloro-m-cresol in pet, may elicit a true positive reaction. TBTO is a strong irritant which will produce delayed bullous reactions in industrial use and on patch testing at 0.1% aqueous.