Allergic contact dermatitis to quaternium 15 in a moisturizing lotion

A 56-year-old nurse from a rural area presented with a 12-month history of hand dermatitis. She had previously been patch tested by a local medical practitioner with the thin-layer rapid-use epicutaneous test, which had shown allergies to quaternium 15 and formaldehyde. After testing, she was prescribed methylprednisolone aceponate 1 mg/g cream by the medical practitioner, but was not informed that quaternium 15 is contained in the Microshield moisturizing lotion she was using at work. When her dermatitis persisted, she saw a dermatologist, who advised her to avoid the Microshield moisturizing lotion, and use a waterless hand cleanser on return to work. The diagnoses were firstly allergic contact dermatitis from quaternium 15 in the moisturizing lotion, and secondly irritant contact dermatitis from nursing work. This case highlights both the presence of quaternium 15 in a product commonly used in health-care settings in Australia, and the importance of offering informed, appropriate advice to patients following patch testing.