Contact allergy and allergic contact dermatitis from benzalkonium chloride in a tertiary dermatology center in Melbourne, Australia

Abstract

BackgroundBenzalkonium chloride (BAK) is a quaternary ammonium compound that is used widely as an antiseptic and preservative. It is a strong irritant and considered a weak sensitizer.ObjectiveTo analyze the temporal trend of BAK sensitization and the demographics of sensitized patients.MethodsWe conducted a single‐center retrospective study of 7390 patients who were patch tested with BAK between January 1, 2003 and December 31, 2019.ResultsOf the 7390 patients who were patch tested to BAK, 108 (1.5%) had a positive reaction, with 21 reactions deemed clinically relevant (0.3% of total patch tested) and a further 5 doubtful reactions deemed clinically relevant, resulting in a total of 26 relevant reactions (0.4% of total patch tested). Common sources of exposure were ophthalmic drops (30.8%), topical antiseptic preparations (26.9%), cosmetics (15.4%), disinfectant solutions (11.5%), hand sanitizers (11.5%), and hand washes (7.7%). One fifth of patients with relevant reactions were health care workers. There has been a dramatic increase in the number of positive reactions since 2017, for reasons not totally clear.ConclusionContact allergy (CA) and allergic contact dermatitis (ACD) in response to BAK are now increasing at our center. Awareness of this trend is important, given that the coronavirus disease 2019 (COVID‐19) pandemic is likely to further expose people to BAK.

Triple relevant sensitization to didecyldimethylammonium chloride, benzalkonium chloride, and polyhexamethylene biguanide in a hospital cleaner

“…2,3 Nevertheless, these quaternary ammonium compounds, as well as PHMB, may cause clinically relevant contact allergy, and all three can also cause immediate-type hypersensitivity. 2,3,[6][7][8][9] The present case illustrates the contact allergenic nature of BAC and DDAC, and underlines the usefulness of using dilution series to demonstrate this. Moreover, it appears that DDAC and BAC are perhaps best patch tested in a pet.-and aq.-based vehicle, respectively.…”

“…Being notorious skin irritants, the interpretation of patch test reactions to DDAC and BAC can be difficult, and false‐positive patch test reactions might occur 2,3 . Nevertheless, these quaternary ammonium compounds, as well as PHMB, may cause clinically relevant contact allergy, and all three can also cause immediate‐type hypersensitivity 2,3,6‐9 . The present case illustrates the contact allergenic nature of BAC and DDAC, and underlines the usefulness of using dilution series to demonstrate this.…”

Quaternary ammonium compounds in hypersensitivity reactions

“…This is probably because it is the most widespread QAC as preservative and antiseptic in medicines, cosmetics, and cleaning agents, but it might also be due to its intrinsic properties. A study of patients with contact allergy and CD found a trend to increase in BAC sensitization in the recent years, and the main sources of exposure were ophthalmic drops, topical antiseptics, and cosmetics ( Dear et al, 2021 ). Moreover, BAC was the sixth allergen giving the highest reaction within a large retrospective cohort of patch testing ( Veverka et al, 2018 ).…”

Allergic contact dermatitis caused by benzalkonium chloride from laundry disinfectant

“…1 It is commonly found as an ingredient in personal care products, including deodorants, cosmetics, mouthwashes, ophthalmic solutions, and nasal sprays. 1 A 26-year-old Chinese woman was referred for recurrent erythematous patches with severe pruritus of 9 months' duration.The lesions began on the antecubital fossa, popliteal fossa, and abdomen and then rapidly spread to the entire body except the face and scalp. She was diagnosed with erythrodermic atopic dermatitis.…”

“…1 It is commonly found as an ingredient in personal care products, including deodorants, cosmetics, mouthwashes, ophthalmic solutions, and nasal sprays. 1 A 26-year-old Chinese woman was referred for recurrent erythematous patches with severe pruritus of 9 months' duration.…”