CHILBLAIN-LIKE ACRAL LESIONS DURING THE COVID-19 PANDEMIC (COVID TOES): HISTOLOGIC, IMMUNOFLUORESCENCE AND IMMUNOHISTOCHEMICAL STUDY OF 17 CASES

Background During the COVID-19 pandemic, several acral chilblain-like skin lesions (CBLL) were observed in young patients with suspected, but mostly unconfirmed, infection with SARS-CoV-2 The histopathological aspect of these lesions is as yet poorly known Objective To investigate the pathologic features of CBLL Methods Biopsies were obtained from 17 cases of CBLL during the COVID-19 pandemic in France and were studied by routine histological examination, immunohistochemistry and direct immunofluorescence (DIF) The patients had suspected but unconfirmed infection with SARS-CoV-2 (negative nasopharyngeal PCR test and serological tests) Results CBLL showed many features with those reported in idiopathic (IC) and auto-immune related chilblains (AC), including epidermal necrotic keratinocytes, dermal edema, perivascular and perieccrine sweat gland lymphocytic (predominantly CD3/CD4+) inflammation and frequent vascular changes (endothelialitis, microthromboses, fibrin deposition, immunoreactant deposits on vessels) Conclusions CBLL show similar histopathologic features with IC and AC, with a rather high rate of vascular changes and DIF positivity The role of SARS-CoV-2 in the development of these puzzling lesions remains to be elucidated