Clinical and Histopathological Features and Potential Pathological Mechanisms of Skin Lesions in COVID-19: Review of the Literature

The document summarized the diverse skin lesions observed in COVID-19 patients, based on a review of 57 articles published between December 2019 and June 2020. It found that skin manifestations varied widely and did not necessarily correlate with disease severity, with a prevalence ranging from 1.8% to 20.4% among patients. The lesions, which included maculopapular eruptions, pseudochilblain, urticarial lesions, and others, typically resolved on their own and appeared 1 to 14 days after COVID-19 symptoms, sometimes even preceding them. Histopathological examinations showed epidermal and dermal vascular lesions, microvascular injury, and thrombosis, suggesting both direct viral effects and immune responses as potential mechanisms. The document also discussed the presence of the virus's receptor ACE2 in the skin and the role of TMPRSS2, which may explain the higher prevalence of lesions in males and a potential link to androgenetic alopecia. The exact pathological mechanisms remain unclear, and further research is needed. The document did not specify the number of people in the study.