The Italian Trend of Contact Allergy to 2-Hydroxyethyl Methacrylate: Is the Current European Legislation Working?

Background: (Meth)acrylates are well-known causes of allergic contact dermatitis, and nail products are the major source of exposure, especially in a non-occupational setting. In 2020, the European legislation restricted 2-hydroxyethyl methacrylate (2-HEMA) only in nail cosmetics to professional use. Objective: To investigate the Italian prevalence trend of positive patch test reactions to 2-HEMA, the best marker for delayed hypersensitivity to (meth)acrylates. Methods: A retrospective descriptive study on consecutive patients patch tested with the Italian baseline series containing 2-HEMA was performed in 8 Italian Dermatology Clinics. Demographics, patch test results, exposure settings and sources were analysed. Results: Amongst 7133 patch tested patients, 147 (2.1%) resulted positive to 2-HEMA with an increasing trend from 2019 (1.6%) to 2023 (2.7%). The median age of sensitised female patients with a relevant positive patch test reaction to 2-HEMA was significantly decreasing over time (p = 0.004). Non-occupational allergic contact dermatitis was documented in 68.7%; artificial nails were the leading source of exposure in both occupational (75.0%) and non-occupational (72.2%) settings. Conclusion: The prevalence of contact allergy to 2-HEMA in Italy shows a progressively increasing trend over time. Currently, the European legislation does not appear to be effective in preventing or reducing this phenomenon.