Allergy experts are warning about an antiseptic responsible for a growing number of harmful and potentially fatal reactions.
Chlorhexidine is a widely used disinfectant and antiseptic, but its presence may be obscured because of inconsistent labelling, a new information booklet from the Australasian Society of Clinical Immunology and Allergy (ASCIA) says.
As a result, allergic reactions to the agent may have gone underappreciated, it says.
“There has been a dramatic increase in the number of chlorhexidine-containing products in hospital and community settings over the last couple of decades,” the booklet says. “As antibiotic-resistant organisms are becoming more common, its use in both prevention and treatment of infection is likely to continue.”
Allergic reactions to chlorhexidine are rare, but immediate allergic reactions can cause itching, urticaria, angioedema and anaphylaxis.
“Anaphylaxis typically occurs when chlorhexidine comes in contact with internal (mucosal) surfaces or deeper tissues in the body, through an opening of the skin during a medical procedure,” the booklet says, pointing to its use as a coating on medical devices, such as central venous lines.
“People who develop anaphylaxis to chlorhexidine may report prior mild hives (urticaria) to chlorhexidine. The significance of these may not have been appreciated.”
Because medical devices may not list it as an ingredient, or use abbreviations such as CHG in dressings or AGB on central venous lines, an allergic reaction may be difficult to diagnose. However, allergy skin tests and blood tests for allergen specific IgE can be used to confirm or exclude
ASCIA encouraged patients with allergies to ask their doctor for an epinephrine autoinjector, such as an EpiPen, if necessary, and discuss an emergency action plan.
Chlorhexidine allergy is a well-recognised cause of anaphylaxis during surgery, but a past history of other allergies does not appear to increase the risk of developing chlorhexidine allergy, the authors write.
It is also unclear whether the frequent exposure that some doctors may have to the antiseptic increases the risk of an allergy, with the authors saying that those with chlorhexidine allergy “should be able to tolerate other antiseptic products due to the lack of cross-reactivity”.
The information sheet lists a number of products in the community that may contain the chemical, including hand gels and washes, mouthwashes, toothpastes and other mouth products, disinfectants or antiseptics, shampoo, body wash, sponges and wipes, skin creams, ointments and cleansers, antiseptic throat lozenges and sprays, nasal sprays and cosmetics.
And in a medical setting, chlorhexidine may be found in skin antiseptic wipes, hand gels and hand wash solutions, surgical skin disinfectants, pre-surgery wash sponges and wipes, surface cleaning sprays and solutions, lubricant preparations, mouthwash, central venous lines, surgical dressings and mesh.