Occupational allergic contact dermatitis from unsaturated polyester resin in a car repair putty

Background Unsaturated polyester (UP) resins are widely used as cements in car repair painting to produce a smooth surface before the final painting. We report two car painters with hand and face dermatitis who were sensitize d to a UP resin used for car repair cements. Methods Patch testing with commercial substances and ingredients and extrac ts from UP resins was used to verify the sensitivity. Results Both patients showed an allergic patch test reaction to a UP resin. They also had an allergic patch test reaction to diethyleneglycol maleate (DEGM), an extract of a UP resin. Conclusions Both patients had been patch tested elsewhere with negative res ults because UP resins had not been used for patch testing. Accordingly, pa tients with dermatitis who have been exposed to UP resins need to be patch tested with UP resins. The specific chemical causing allergic contact derma titis in our patients was DEGM.