To the Editor: Chlorhexidine (CHL) is a widely used broad?spectrum antiseptic and disinfectant. First used as a topical antimicrobial agent, CHL is now available in different forms and is present in various settings.[1] CHL has the potential to cause Type Ⅰ and Type Ⅳ hypersensitivity reactions, varying from mild cutaneous reactions to anaphylaxis.[2] An increased recognition of CHL?induced hypersensitivity parallels the increased use of CHL in medical care and the increased awareness of allergy.[3] CHL is an important but easily overlooked allergen, and a provocation test (which serves as the gold standard) is usually difficult to perform. Here, we report a rare case of provocation test?confirmed CHL anaphylaxis during a dental procedure.