The global coronavirus disease pandemic (COVID-19) has led to an increased need to wear protective equipment such as wearing face masks and practicing hygiene measures such as more frequent use of antiseptics. These measures can lead to changes in the skin, the development of new inflammatory skin diseases or exacerbation of existing ones, with health professionals especially under the risk of developing these changes. Changes in facial skin due to wearing masks have been observed in a number of studies, however, part of the study was based solely on subjects' self-assessment or clinical assessment, and only a small part on objective measurements of skin parameters. Also, the impact of prolonged masks' use have not been investigated.

The aim of these study was to investigate the effects of constant, long-term use of protective masks on facial skin.

Inclusion Criteria:

• young, healthy volunteers who gave written informed consent - students of health related professions who wear facial mask for at least six hours a day durnig their internship/practice in health care institutions

Exclusion Criteria:

• skin disease, skin damage on measurement sites
• use of corticosteroids, antihistamines and immunomodulators a month prior the inclusion and during the trial
• use of emollients three days prior the inclusion in the trial
• non-adherence to the trial protocol
• exposure to artificial and excessive natural UV radiation
• pregnancy and lactation
• skin cancer
• immunosuppression

Healthy students of health related professions who wear facial mask daily for at least six hours durnig their internship/practice in health care institutions.