Acetophenone Azine: The 2021 American Contact Dermatitis Society Allergen of the Year.

The American Contact Dermatitis Society chose acetophenone azine (AA) as the 2021 Allergen of the Year. Acetophenone azine is an emerging contact allergen that often is associated with the use of sports equipment and footwear. The pattern of dermatitis initially starts locally at the site of contact but can develop into a generalized dermatitis. Strong suspicion is necessary to diagnose AA allergy, and patch testing should be completed with AA and to potentially relevant sports equipment and/or shoes. Acetophenone azine is not yet available as a commercial patch-test preparation, but the optimal concentration is 0.1% in acetone or petrolatum. This column serves as an introduction to AA as an emerging allergen and highlights diagnosis, management, and patch testing for AA contact allergy.