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Benzalkonium Chloride: An Irritant and Sensitizer

Jahdonna Isaac¹, Pamela L Scheinman

¹From the *Tufts University School of Medicine and †Department of Dermatology, Brigham and Women's Hospital, Boston, MA.

Dermatitis : Contact, Atopic, Occupational, Drug

|September 9, 2017

Summary

Benzalkonium chloride (BAK) is a common preservative in personal care products. Over 30% of patients with suspected allergic contact dermatitis showed positive reactions to BAK, indicating a need for careful product selection.

Area of Science:

Dermatology
Allergology
Toxicology

Background:

Benzalkonium chloride (BAK) is a widely used preservative in personal care products.
BAK and related quaternary ammonium compounds are known irritants and potential allergens.

Observation:

A retrospective chart review analyzed 615 patients patch tested for suspected allergic contact dermatitis.
Patients were tested with a core series of 70 allergens, including BAK (0.1% aqueous).
Reactions were graded at 48 hours and again between 72 and 168 hours.

Findings:

Of 615 patients, 198 (32%) tested positive for Benzalkonium chloride.
Ten percent of patients exhibited strong or extreme reactions (++/+++) to BAK.
Patients with positive BAK reactions were frequently using products containing BAK or similar compounds.

Implications:

Widespread exposure to irritants like BAK may increase susceptibility to sensitization in dermatitis patients.
Individuals with compromised skin barriers should exercise caution when using products containing BAK or potential cross-reactors.
This study highlights the prevalence of BAK sensitivity in patients with allergic contact dermatitis.

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