Immunological Contact Urticaria and Anaphylaxis to Chlorhexidine: Overview

Abstract

For more than 50 years chlorhexidine has been widely used as a medical disinfectant, as an additive for wound dressings or as a preservative in many cosmetic products, personal care products and drugs. In the last two decades, reports of immediate-type reactions to chlorhexidine reaching from localized urticaria to anaphylactic shock began to appear more frequently. However, the prevalence of contact urticaria and anaphylaxis due to chlorhexidine remains unknown. In this article, we reviewed the literature using PubMed, entering queries for ‘chlorhexidine anaphylaxis’, ‘chlorhexidine contact urticaria’ and ‘chlorhexidine allergy’. In total we reviewed 66 case reports. Twenty reactions occurred when chlorhexidine was applied to damaged skin surfaces, 27 patients showed an immediate-type reaction when chlorhexidine was applied to mucous membranes. Sixteen reports, all but one of them from Japan, concerned anaphylactic reactions after introduction of a chlorhexidine-coated central venous catheter. Slight damage to the epidermal barrier or application to mucous membranes seems to enhance the immediate reaction to chlorhexidine. Life-threatening shocks may be provoked even by application of chlorhexidine at its lowest bactericidal concentration. The diagnosis was confirmed by prick testing, intradermal testing or scratch testing. In 16 case reports, more than one severe immediate-type reaction occurred, because chlorhexidine had not been identified as the cause of one or more earlier episodes, suggesting that severe anaphylactic reactions to chlorhexidine are still not well recognized.

Anaphylaxis after disinfection with 2% chlorhexidine wand applicator

“…In most instances, the source of systemic absorption is an area of skin barrier compromise such as a burn,17 a wound18 or dermatitis 19…”

Chlorhexidine and hypersensitivity reactions in dentistry

“…In the medical literature, reactions have mainly been recorded in case reports with these cases falling into three broad categories. 14 Type I hypersensitivity reactions have been reported when chlorhexidine has been applied to damaged skin surfaces. 8,10,14 These instances include wounds and burns or when the skin was cut in surgical procedures and a chlorhexidine containing product had been used in the preparation of the skin.…”

Allergic urticaria: A case report of rare skin allergy with a common mouthwash

“…[9] Twenty reactions occurred when chlorhexidine was applied to damaged skin surfaces and 27 patients showed an immediate type reaction when chlorhexidine was applied to mucous membranes. Similarly two cases of mucosal sensitivity to contact with chlorhexidine were reported by Yusof and Khoo.…”