A Dermatologic Manifestation of COVID-19: Transient Livedo Reticularis
Case 1: A 67-year-old Caucasian male was hospitalized for COVID-19 (nasopharyngeal swab PCR-confirmed) management. His symptoms began 10 days prior with low-grade fever, nasal congestion, post-nasal drip, and cough without shortness of breath. Seven days into his symptoms, he noted a transient non-pruritic blanching unilateral livedoid patch on the right anterior thigh resembling LR (Figure 1). The eruption lasted for 19 hours and resolved by the time dermatology evaluated the patient; thus no biopsy was taken. Concurrent with the lacy patches on the leg, the patient also noted gross hematuria and generalized weakness. In concert with the netlike exanthem, the hematuria resolved within 24 hours. He was eventually discharged home stable on supplemental oxygen. Case 2: A 47-year-old Caucasian female with history of Celiac disease, Hashimoto’s thyroiditis, and portal vein thrombosis in 2017 with negative work-up for a hypercoagulable state (attributed to a long plane flight combined with prior oral contraceptive) tested COVID-19-positive. Symptoms began with a mild headache, sinus pressure, anosmia, and fever, with highest recorded temperature of 37.9°C. Ten days after testing positive, and with complete clinical convalescence of COVID-19 symptoms, she was sitting outside in long pants under direct sunlight for approximately 20-30 minutes. A unilateral asymptomatic rash on her right leg resembling LR was noticed incidentally immediately upon moving indoors (Figure 2) despite an equal amount of sun exposure on both legs. The rash lasted approximately 20 minutes and did not recur upon re-challenge with sun exposure the following day. Discussion Livedo reticularis is caused by conditions, including disseminated intravascular coagulation (DIC), that reduce blood flow through the cutaneous microvasculature system leading to deoxygenated blood accumulation in the venous plexus.3 We hypothesize that the microthromboses that manifest in other organs (e.g. cardiopulmonary)4 and as DIC2,5 in critically ill COVID-19 patients are the most plausible etiology to our patients' LR presentations. We postulate that manifestations can vary from transient LR in mild-moderate cases to acrocyanosis in critically ill patients. Because our patients were not critically ill, perhaps they had transient low-grade DIC, and the concurrent hematuria in Patient 1 could be explained by a possible micro-embolic event causing glomerulonephritis or cystitis. However, due to the evanescent nature of their LR-like eruptions, they were not biopsied. Interestingly, exanthems have not been described for other coronaviruses such as SARS-CoV and MERS-CoV. In the future, histopathology of active exanthema may be helpful in elucidating the underlying pathology of the cutaneous and perhaps systemic manifestations of COVID-19 infection. Additionally, platelet count, coagulation studies, and fibrin degradation products assessments in these patients would be enlightening.