An Autopsy Review: "COVID Toes"

"Severe acute respiratory syndrome coronavirus-2" (SARS-CoV-2) infection has variable described dermatologic manifestations. "COVID (coronavirus disease) toes" became a hallmark of the disease in young and largely asymptomatic patients, who may have negative test results for SARS-CoV-2. Pernio (chilblains)-like lesions are seen mostly in infected pediatric patients and are purple painful, frequently bilateral, ill-defined plaques with prominent inflammation on histological examination. In contrast to pernio-like presentation in children, critically ill adult patients with SARS-CoV-2 develop "purple" digits that may be sharply demarcated and may demonstrate asymmetric areas of ischemia. These 2 contrasting entities are sometimes grouped together as "COVID toes" due to some similarities in clinical appearance and presentation. Here, we summarize histopathologic examination from an autopsy, including the cutaneous lesions from the affected and normal contralateral toes and correlate them with systemic findings. In contrast to pernio-like lesions, the skin of the affected necrotic toes contained thrombi in vessels without prominent inflammation, suggestive of an embolic event. This is further supported by the clinical history of and autopsy findings of popliteal artery thrombus and multiple subsegmental pulmonary emboli. Our findings suggest that critically ill patients with SARS-CoV-2 have different pathological processes affecting skin at peripheral sites (ie, fingers, toes, ears, and nose), which may be due to thromboembolic events. The skin is a mirror of the body and skin pathology may shed light into overall pathogenesis of systemic illness and processes.