Effects of one year of daily face mask wearing on the skin during the coronavirus disease 2019 pandemic

Background As coronavirus disease 2019 (COVID-19) continues, the long-term daily use of masks is increasing. A full year includes the four seasons of spring, summer, autumn, and winter. Skin may have been affected by the seasons and further affected by the use of masks. In a previous study, we confirmed the short-term and 6-month effects of wearing face masks. In this study, we investigated how certain characteristics of the skin change when wearing a mask for 1 year. Furthermore, we compared skin covered by the mask (mask-skin zone) to skin that was not covered. Materials and methods The participants were 18 healthy adults (8 men; 10 women) who were asked to wear masks in their daily lives from June 2020 to June 2021. During this period, participants' skin characteristics, such as trans-epidermal water loss, skin hydration, skin elasticity, skin keratin amount, skin pore area, skin temperature, skin redness, and skin color, were measured five times. Results Trans-epidermal water loss, skin keratin amount, skin pore area, skin color, and skin elasticity changed significantly during the year. Furthermore, trans-epidermal water loss, skin hydration, skin keratin amount, skin pore area, and skin color were significantly different between the mask-wearing and non-mask-wearing areas of the face. Conclusion The skin characteristics of the mask-skin zone can be affected by long-term wearing of a face mask under lifestyle and environmental conditions. During the COVID-19 pandemic, skin care for the mask-skin zone is also necessary for people who do not wear masks on a daily basis.