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

Abstract

Background: Benzalkonium 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. Objective: To analyze the temporal trend of BAK sensitization and the demographics of sensitized patients. Methods: We conducted a single-center retrospective study of 7390 patients who were patch tested with BAK between January 1, 2003 and December 31, 2019. Results: Of 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..