Contact allergy investigations in healthcare workers with face mask-related skin disease

Background: During the COVID-19 pandemic, the use of face masks has increased among healthcare workers (HCWs). Questionnaire studies have shown a high frequency of self-reported facial adverse skin reactions. Case reports have been published on face mask-induced allergic contact dermatitis and urticaria.Objectives: To describe the results of the contact allergy investigations in consecutive HCWs investigated for skin reactions to face masks during the COVID-19 pandemic and the results of the chemical investigations of face masks supplied by the hospital.Methods: Participants were patch tested with baseline series and chemicals previously reported in face masks not included in the baseline series. Face mask(s) brought by the HCW were tested as is and/or in acetone extract. Chemical analyses were performed on nine different face masks for potential allergens.Results: Fifty-eight HCWs were investigated. No contact allergies were found to the face mask(s) tested. Eczema was the most common type of skin reaction, followed by an acneiform reaction. Colophonium-related substances were found in one respirator and 2,6-di-t-butyl-4-methylphenol (BHT) were found in two respirators.Conclusion: Based on this report, contact allergies to face masks is uncommon. Patch test with colophonium-related substances and BHT should be considered when investigating adverse skin reactions to face masks.