The use of cleansers and chemicals is a leading cause of the aggravation of atopic dermatitis (AD) for patients with atopic diatheses. However, disinfection using hand antiseptic agents is essential for medical practitioners and food handlers, even for those with this condition. In current practice, quick-drying hand antiseptic gels are recommended because they are time-saving, easy to use, and provide the same bacterial eradication rate as hand washing with tap water and detergent [1]. An additional advantage is that the quick-drying active ingredients remain on the skin and continue the disinfection effect. However, a potential negative effect is that the active ingredients will irritate the skin because of their continued presence on the skin surface.
As a cationic detergent in the family of quaternary ammonium compounds, benzalkonium chloride (BZK) shows strong antiseptic activity against both gram-positive and -negative bacteria. In terms of skin sensitization, the irritant action of BZK has been shown to be minimal and more gentle than that of ethanol-based antiseptics [2-4]. Hand sanitizers containing BZK are widely available in various settings, including hospitals, restaurants, and shopping centers. However, contact dermatitis due to BZK has been reported. In particular, previous case studies have reported the occurrence of erythematous rash, eczema, and blistering on the face, trunk, and limbs after using shampoo, plaster of Paris bandages, or antiseptic bath oil containing BZK [5-7].