The variety of observed dermatoses and skin rashes can be divided into seven groups depending on their etiology and development mechanisms:
Group 1 – Skin Angiitis. They are directly caused by a coronavirus infection, against the background of which the walls of the small vessels of the dermis are damaged by circulating immune complexes in the form of deposits with infectious (viral) antigens. Special forms associated with COVID-19 infection include acrovasculitis. The acral confinement of the rash is probably due to concomitant hypoxia against the background of extensive lung damage.
Group 2 – Papulosquamous rashes and pityriasis rosea. They are infectious and allergic skin lesions associated with a COVID-19 infection. A clinical feature of pityriasis rosea in coronavirus infection is the absence of a “herald patch”.
Group 3 – Measles-like rashes. In case of COVID-19 infection, these rashes resemble, in their clinical characteristics, the rashes that occur with measles, and, thus, indicate a pathogenetic proximity to other viral exanthema.
Group 4 – Papulovesicular rashes (as miliary or eccrine sweating fever). They occur against the background of subfebrile condition with multi-day increased sweating in patients. In contrast to the classical course of miliary, characterized by the vastness of lesions of the skin.
Group 5 – Toxidermia. They are not directly associated with coronavirus infection and are the result of individual patients intolerance to certain drugs. Compared with antibacterial and combined antiviral drugs, hydroxychloroquine less often causes allergic skin reactions in the treatment of coronavirus infection.
Group 6 – Urticaria. Depending on its origin, the disease can be twofold. On the one hand, urticarial rashes may be a first warning of the onset of COVID-19 infection or occur along with its first symptoms. On the other hand, urticaria often develops due to drug intolerance and, in this case, refers to one of the clinical manifestations of toxidermia. The acral arrangement of the blisters against the background of COVID-19 infection can also be attributed to the specific features of the urticarial skin lesion in this viral disease.
Group 7 – Artificial lesions (trophic changes in facial tissues). They are the result of a forced long stay of patients in a pron-position in order to improve respiratory function.
The material will be useful for practicing internists and general practitioners. Recognition of early dermatological symptoms of coronavirus infection will help its early diagnosis.