Allergic contact dermatitis due to a herbicide (barban).

Canadian farmers are using increasing amounts of herbicides. Often they do not use adequate skin protection. Two cases of severe allergic contact dermatitis due to the herbicide barban are described. Patch testing with various substances, including barban, confirmed the diagnosis. Sensitization studies in guinea pigs and in one of the authors showed that barban is a potent sensitizer. It is recommended that if skin contact with barban occurs the skin be washed immediately with soap and water.