Chlorhexidine and hypersensitivity reactions in dentistry.

Immunological reactions to chlorhexidine, including allergy (Type I hypersensitivity) and allergic contact dermatitis/stomatitis (Type IV hypersensitivity), have been recognised for many years. This potential safety issue, however, is not well known within dentistry. The purpose of this paper is to alert dentists and dental care professionals to the potential of chlorhexidine in causing hypersensitivity reactions and to consider this possibility if unexplained hypersensitivity reactions occur.