1.2 Virus induced vesicular eruptions
Virus induced vesicular eruptions are quite common for herpes simplex virus or varicella zoster virus induced skin lesions in which the vesicles are caused by intraepidermal blister and epithelial necrosis. Either reticular degeneration of the epidermis or ballooning of keratinocytes might cause intraepidermal vesicle formation (53, 54 ) (Table 2). Another example for virus induced vesicular eruptions are caused by Coxsackie A16 virus, an enterovirus, which is responsible for Hand-foot-and mouth diseases. Intraepidermal vesicles with reticular degeneration and ballooned cells are characteristic features. Papillary edema and mild perivascular infiltrates might be detectable as well. In all of those virus induced skin eruptions, viral antigens are detectable in various cutaneous structures using different methods such as antibody staining, electron-microscopy or others (53, 54 ).
Whether vesicular eruptions observed in part of the COVID-19 patients are caused by SARS-CoV-2, needs to be evaluated in further studies.
Some reports of erythemato-violaceous papules and patches with a pseudo-vesicle in the center, resembling erythema-multiforme and an enanthem of the oral cavity in some of those patients during or after improvement of COVID-19 symptoms exist (55-58 ). If those lesions are related to SARS-CoV-2 infection or drugs applied in this context or both remains to be elucidated in further studies.