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.
To investigate the pathologic features of CBLL.
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).
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).
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.