Abstract

A 23-year-old woman with a history of recently diagnosed lupus erythematosus presented with memory deficit and a painful livedoid rash on the bilateral feet for 3 weeks. Differential diagnosis of the skin lesions at the time of presentation included livedo reticularis, chilblain lupus, and livedo racemosa. Biopsy of a plantar foot lesion revealed subendothelial proliferation of smooth muscle actin positive cells and endothelial cell hypertrophy in dermal medium-sized arteries and arterioles with partial to complete luminal occlusion and focal thrombosis. MRI was negative for intracranial hemorrhage, infarction, mass, or enhancement. This constellation of histopathologic and clinical findings fits most consistently with Sneddon syndrome, a rare chronic neurocutaneous vasculopathy that affects young women aged 20-40. The incidence of Sneddon syndrome is estimated to be 4 new cases per year per 1 million people. The vasculopathy observed within the dermal arteries of the livedoid lesions are similarly present in cerebral arteries, leading to deficits in concentration, attention, visual perception, and visuospatial skills. Sneddon syndrome is often associated with autoimmune diseases such as systemic lupus erythematosus and antiphospholipid antibody syndrome. Treatment is commonly with antiplatelet and antithrombotic agents. Prognosis is generally poor.