Allergic contact dermatitis from chlorhexidine.

Although chlorhexidine is a widely used substance, allergic contact dermatitis from chlorhexidine has rarely been reported. Our objective was to study all cases of allergic contact dermatitis from chlorhexidine that were seen at St John's Institute of Dermatology from January 1983 to June 2002. The case records of all patients with positive patch-test reactions to chlorhexidine during the study period were retrieved. The clinical presentation, strength, and relevance of the positive patch-test results as well as possible sources of exposure were studied. There were five cases of allergic contact dermatitis from chlorhexidine during the study period; three of these patients had positive patch-test reactions to chlorhexidine that were of current relevance. The possible sources of exposure included Hibisol, Hibiscrub, a chlorhexidine spray, and peri- and postoperative antiseptic solutions. We concluded that allergic contact dermatitis from chlorhexidine is rare. However, when it occurs, it may cause a severe dermatitis reaction.