Cutaneous manifestations of COVID-19
Cutaneous manifestations of COVID-19 are characteristic signs or symptoms of the Coronavirus disease 2019 that occur in the skin. The American Academy of Dermatology reports that skin lesions such as morbilliform (measles-like rashes, 22%), pernio (capillary damage, 18%), urticaria (hives, 16%), macular erythema (rose-colored rash, 13%), vesicular purpura (purplish discolouration, 11%), papulosquamous purpura (discolouration with scale. 9.9%) and retiform purpura (blood vessel obstruction and downstream ischaemia, 6.4%) are seen in people with COVID-19. Pernio-like lesions were more common in mild disease while retiform purpura was seen only in critically ill patients. The major dermatologic patterns identified in individuals with COVID-19 are urticarial rash, confluent erythematous/morbilliform rash, papulovesicular exanthem, chilbain-like acral pattern, livedo reticularis and purpuric "vasculitic" pattern. Chilblains and Multisystem inflammatory syndrome in children are also cutaneous manifestations of COVID-19.
Hyperactive immune responses in COVID-19 patients can contribute to the induction "cytokine storm" (in particular, IL-6); these cytokines could enter the skin and trigger dermal dendritic cells, lymphocytes, macrophages, mast cells, and neutrophils, and can assist in the development of lesions such as maculopapular rash. This representation of cutaneous lesion has been described earlier in diseases having an overactive immune response and excessive cytokine release (example, systemic lupus erythematosus, adult Still's disease, and antiphospholipid syndrome).