Relapsing symmetric livedo reticularis in a patient with COVID-19 infection.

Editor

During the Coronavirus 2019 (COVID‐19) pandemic, several associated skin conditions were reported in infected patients, including, urticaria, exanthema, erythema multiforme, chickenpox‐like vesicles, pityriasis rosea, erythema nodosum like Sweet's syndrome, symmetrical drug‐related intertriginous and flexural exanthema, petechial rash, vasculitic purpura, acro‐ischaemia/necrosis, Kawasaki disease and chilblain lesions.

We present a 57‐year‐old man with cough, dyspnoea, headache, myalgia arthralgia, fever up to 38.7 °C and abdominal pain worsening over 8 days. Extensive, symmetric livedo reticularis (LR) was present on trunk and thighs (Figs 1, 2). Laboratory testing showed elevated C‐reactive protein, ferritin, D‐dimers and lymphopenia. Nasopharyngeal PCR detected SARS‐CoV‐2, and chest CT showed multifocal ground glass opacities, suggestive for COVID‐19. Because of the unusual sudden onset of symmetric LR in a middle‐aged man, an additional workup for underlying conditions was performed. While antineutrophilic cytoplasmic antibodies, platelets, INR/APTT, rheumatoid factor, cryoglobulins and antiphospholipid antibodies were negative, antinuclear factor (ANA) was positive with nuclear pattern (titre 1/320, but without ENA‐blot specificity). The patient's previous ANA titre was unknown, and so far, it has not been investigated whether COVID‐19 can induce such antibodies (as described in other viral disease ). Infectious causes of livedo including HIV, mycoplasma pneumonia, syphilis, Legionella pneumophila, influenza A/B, RSV and hepatitis B/C were negative. During 8 days, oxygen, acetaminophen, hydroxychloroquine and low‐molecular weight heparin in preventive dosing were administered. After discharge, livedo fluctuated, but progressively weaned. At 3 weeks follow‐up, inflammatory parameters were normal (besides insignificantly elevated ferritin), while the patient still experienced slight dyspnoea on exertion.

Figure 1

Symmetric regular lace‐like network on the legs and trunk.

Figure 2

(a) Symmetric regular lace‐like network on the trunk. (b) Symmetric regular lace‐like network on the left leg.

Livedo reticularis describes a regular, lace‐like network of non‐fixed, dusky patches forming complete rings surrounding a pale centre. This clinical picture is caused by constriction of central arterioles and subsequent peripheral venodilation. LR is rarely associated with underlying diseases. It is mostly seen in healthy young woman as a physiological reaction triggered by cold‐induced vasospasms and is then named cutis marmorata. When LR is not influenced by cold exposure, it is called primary LR. A congenital form is referred to as cutis marmorata telangiectatica congenita. When livedo presents as a non‐symmetric, localized, mostly unilateral and irregular network with broken rings, it is named livedo racemosa (LRC). LRC is associated with more significant reduction in blood flow caused by protracted arteriolar vasospasm, thrombosis and/or hyperviscosity. LRC is always a red flag for an underlying pathology, such as vasculitis, autoimmune disease, infection, systemic disorders and neoplasia.

Our patient had a first occurrence of a symmetric, fluctuating, unsuspicious‐looking LR in the context of COVID‐19, without other causes. Livedo was not blanching on pressure and typical clinical signs of vasculitis, like purpura, (asymmetric) LRC or skin necrosis were absent. COVID‐19 can cause a procoagulant state, with small blood vessel occlusion. However, the absence of purpura and skin necrosis together with normal coagulation parameters makes thrombi unlikely as cause of the observed LR. This suggests the presence of low‐grade vascular inflammation and vasodilation caused by direct SARS‐CoV‐2‐infection of endothelial cells or vessel‐associated smooth muscle cells. Both cell types express angiotensin‐converting enzyme 2‐receptor on their surface, the target of SARS‐CoV‐2‐spike protein.

In addition to previously reported two cases of asymmetric/unilateral and transient livedo, our case identifies a symmetric, fluctuating, relapsing, non‐blanching LR as a warning sign for COVID‐19. If symmetric LR occurs for the first time in patients without any risk factors, it warrants the search for underlying pathology, including COVID‐19.

Conflicts of interest

There is no conflict of interest to disclose.

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