Acetophenone azine: a new allergen responsible for severe contact dermatitis from shin pads

Background. Contact dermatitis resulting from the use of shin pads is usually caused by rubber components, dyes, benzoyl peroxide, or formaldehyde resins. Objectives. To investigate and identify a new allergen in shin pads that was responsible for severe contact dermatitis in a young football player. Methods. High-performance liquid chromatography ( HPLC) of samples of shin pads was performed. The boy was patch tested with pieces of shin pads and with acetophenone azine, a chemical substance identified by HPLC in the foam of the shin pads. Results. HPLC identified acetophenone azine at concentrations of approximately 20 mu g/g of shin pad samples. Patch tests gave strongly positive reactions to pieces of shin pads and to acetophenone azine down to 0.001% in acetone, whereas acetophenone and hydrazine sulfate were both negative. Twenty controls were negative for acetophenone azine 0.01% in acetone. Conclusions. Acetophenone azine is a new, strong allergen of shin pads, and more generally of other sport equipment based on ethylene vinyl acetate. It may be used as a biocide, but this has to be confirmed. Further investigations are needed to understand factors such as exposure, cross-reaction patterns, metabolism, and the optimal patch test preparation.