Skin involvement in Susac's syndrome.

Susac's syndrome (SS) is a rare microangiopathy affecting the precapillary arterioles of the brain, retina and inner ear, presumably resulting from an autoimmune endotheliopathy. We report the first case of SS with histologically proven skin involvement, in a 24-year-old male who presented a subacute encephalopathy, branch retinal artery occlusions and bilateral hearing loss, two weeks after the onset of a livedo racemosa of the flanks and feet. Skin biopsies revealed a thrombus in several dermal arterioles, endothelial cells swelling and a mild perivascular lymphocytic infiltrate, which correspond to the same histological findings as previously observed in brain but also in muscle biopsies of patients with SS. A complete recovery was achieved in 4 months with corticosteroids. Follow-up MRI showed centro-callosal "holes". Skin involvement in SS has pathological plausibility since serum antibodies directly binding to central nervous system but also to generic endothelium cells have been reported. Our report supports that SS is a systemic disease that could affect other organs in addition to the brain, retina and inner ear. We suggest careful skin examination should be considered in patients with a suspicion of SS.