No contact allergy to acrylic acid and methacrylic acid in routinely tested dermatitis patients.

Occupational and non-occupational contact allergy to, and allergic contact dermatitis caused by, acrylates/methacrylates are frequently reported (1–18). However, there is no acrylate/methacrylate test preparation in the European baseline patch test series (19). Therefore, contact allergy to, and allergic contact dermatitis caused by, acrylates/methacrylates may be overlooked when the decision is made on what to patch test with in diagnostic work-up of dermatitis patients (5). There are many sensitizing acrylates/methacrylates to consider regarding whether an acrylate/methacrylate preparation should be included in the European baseline patch test series. Therefore, patch testing with a mix of the acrylates/methacrylates with the highest contact allergy rates when they are routinely tested has been tried, but has been unsuccessful (7). Recently, an Italian article reported contamination with acrylic acid in an electrode gel to be the likely cause of the allergic contact dermatitis (18). The patient reacted positively to a few methacrylates not present in the gel, and these were interpreted as cross-reactions. At least theoretically, acrylic acid and methacrylic acid could be formed by the hydrolysis of acrylates and methacrylates in the skin. Therefore, the acids could be major possible hapten(s) concerning contact allergy to acrylates/methacrylates. To test this hypothesis, in this study the acids were routinely tested in dermatitis patients.