Development of sacral/buttock retiform purpura as an ominous presenting sign of COVID‐19 and clinical and histopathologic evolution during severe disease course

Abstract

Retiform purpura has been described as a relatively frequent cutaneous finding in patients with coronavirus disease 2019 (COVID‐19). The etiology is hypothesized to be related to thrombotic vasculopathy based on lesional biopsy specimen findings, but the pathogenesis of the vasculopathy is not completely understood. Here, we present a case of a retiform purpuric patch on the sacrum/buttocks in a hospitalized patient prior to subsequent diagnosis of COVID‐19 and an eventual fatal disease course. Two lesional biopsy specimens at different time points in the disease course revealed thrombotic vasculopathy, despite therapeutic anticoagulation. Detailed histopathologic evaluation using immunohistochemical markers suggest the etiology of the vasculopathy involves both persistent complement activation and platelet aggregation, which possibly promote ongoing thrombus formation. This case highlights that sacral/buttock retiform purpuric patches may be a presenting sign of infection with SARS‐CoV‐2 virus and may represent an ominous sign supporting a future severe disease course. In addition, biopsy specimen findings at separate time points demonstrate that cutaneous vasculopathy may persist despite adequate systemic anticoagulation, possibly due to the combination of persistent complement and platelet activation. Finally, occlusive thrombi in sacral/buttock retiform purpuric patches may contribute to future ulceration and significant cutaneous morbidity in patients who survive COVID‐19.

Abnormal thrombosis and neutrophil activation increases the risk of hospital-acquired sacral pressure injuries and morbidity in patients with COVID-19

“…Although these events typically do not appear to result in significant skin damage, they may promote eventual ulceration in areas like the sacrum that are additionally affected by pressure. In support of this, we have previously seen and reported several patients with severe COVID-19 who developed unusual retiform purpura on the buttocks associated with histologic thrombotic vasculopathy and subsequent development of sacral ulcers ( 11, 13 ).…”

“…Despite the frequent presence of common HASPI risk factors, our clinical experience is that some COVID-19 patients acquire HASPIs that develop and progress more rapidly than usual, and which may be associated with retiform purpura ( 11, 13 ). Based on these observations, we hypothesized that factors inherent to SARS-CoV-2 infection contribute to formation of HASPIs in some COVID-19 patients.…”

What Do We Need to Know About Musculoskeletal Manifestations of COVID-19?

“…We found case reports and series associating COVID-19 with various rheumatological conditions such as seronegative rheumatoid arthritis, psoriatic arthritis, dermatomyositis-lupus overlap syndrome, axial spondyloarthritis, peripheral spondyloarthritis, and reactive arthritis 71,77,82,83,87 . There are also newly described conditions that seem to have a rheumatological background: sacral/buttock retiform purpura and pernio-like/“COVID-19 toes.” 75,89 Fibromyalgia and urticarial vasculitis with musculoskeletal manifestations are also mentioned in the literature 17,41 .…”

“…An interesting entity reported by McBride et al is retiform purpura on the sacrum and buttocks, which may represent a clinical sign indicative of infection with SARS-CoV-2 and possibly even a predictor of severity 89 . This manifestation is a cutaneous thrombotic lesion with branching, non-blanching patches or plaques on the skin of the sacrum accompanied by intergluteal hyperpigmentation.…”

“…There are also newly described conditions that seem to have a rheumatological background: sacral/buttock retiform purpura and pernio-like/"COVID-19 toes." 75,89 Fibromyalgia and urticarial vasculitis with musculoskeletal manifestations are also mentioned in the literature 17,41 .…”