Sneddon Syndrome: A Comprehensive Overview

Abstract

Sneddon syndrome (SS) is an episodic or chronic, slowly progressive disorder and characterized by generalized livedo racemosa (patchy, violaceous, skin discoloration) and recurrent cerebrovascular events. The histopathology of skin and brain is remarkable for a noninflammatory thrombotic vasculopathy involving medium- and small-sized dermal and cerebral arteries, respectively. Approximately 80% of the SS patients are women with a median age of diagnosis at 40 years. However, the onset of the disease during childhood have been reported. Etiopathogenesis of SS is unknown with 2 primary mechanisms proposed - autoimmune/inflammatory versus thrombophilia. SS is primarily classified as antiphospholipid positive or negative type. Neurological manifestations usually occur in 3 phases: (1) prodromal symptoms such as headaches, dizziness, and vertigo, (2) recurrent strokes, and (3) early onset dementia. Livedo racemosa precedes the onset of recurrent strokes by more than 10 years, but in many instances, the significance of the skin lesion is recognized only after the appearance of the stroke. The involvement of the heart valves, systolic labile hypertension, and retinal changes are also commonly associated with this syndrome. Treatment of SS is primarily based on anecdotal reports. Antiplatelet and antithrombotic agents are used for secondary stroke prophylaxis, and a recent study showed a relatively lower stroke recurrence rate with the universal use of antiplatelet/antithrombotic agents. Routine use of anti-inflammatory or immunosuppressive therapies is controversial. Neuropsychiatric prognosis of SS is relatively poor with predominant deficits in the concentration, attention, visual perception, and visuospatial skills.

Keywords: Sneddon syndrome; antiphospholipid antibodies; dementia; ischemic strokes; livedo racemosa; thrombophilia.