The clinicopathological spectrum of COVID-19-associated cutaneous manifestations: an Italian multicenter study of 197 adult patients

Background: COronaVIrus Disease 19 (COVID-19) is associated with a wide spectrum of skin manifestations. Objective: To describe clinical and histopathological findings of COVID-19-associated cutaneous manifestations and to explore the relationship between cutaneous phenotypes and systemic findings of COVID-19. Methods: Twenty Italian Dermatology Units were asked to gather demographic, clinical and histopathological data of patients with COVID-19-associated skin manifestations. Results: Data of 197 patients with COVID-19-related dermatologic manifestations were collected. The most frequent cutaneous phenotypes were the confluent erythematous/maculo-papular/morbilliform rash (n=54; 27.4%) and chilblain-like acral pattern (n=50; 25.4%). Chilblain-like acral pattern, which were more frequent in young patients, was positively associated with the asymptomatic status (φ= 0.55; p< 0.0001) and negatively associated with disease severity (φ= -0.33; p< 0.0001). On histopathology, microthrombi were a hallmark of the vasculopathic/vasculitic pattern, including chilblain-like acral pattern, purpuric "vasculitic" pattern and livedo reticularis/racemosa-like pattern. Limitations: The retrospective nature of the study made it difficult to collect histopathological data in all cases. Laboratory confirmation of COVID-19 was not possible in every patient. Conclusions: Six main clinicopathological phenotypes of COVID-19-associated skin manifestations have been identified. Further studies are needed to better characterize the pathomechanisms underlying these cutaneous phenotypes and their relationship with the extracutaneous manifestations.