Sneddon's syndrome

Severe, transient neurological symptoms or stroke
Livedo reticularis, or livedo racemosa

Sneddon's syndrome generally manifests with stroke or severe, transient neurological symptoms, and a skin rash (livedo reticularis). Livedo reticularis appears as a bluish purple, netlike mottling of the skin. Sneddon's syndrome may instead present with livedo racemosa, which involves larger, less organized patches of bluish purple mottling of the skin. Both are generally found first in the extremities, both worsen in cold and either may occur without Sneddon's syndrome or any other systemic disease. Sneddon's syndrome can be characterized by: transient amnesia, transient aphasia, palsy, headaches, hypertension, transient ischemic attacks (TIA), stroke, The skin manifestations may precede the neurologic symptoms by years.

Sneddon's syndrome is a progressive, noninflammatory arteriopathy leading to the characteristic skin condition and to cerebrovascular problems, including stroke, transient ischemic attack (TIA), severe but transient neurological symptoms thought to be caused by cerebral vasospasm, coronary disease and early onset dementia. Progressive compromise of arterial linings in Sneddon's produces clotting, for which high dose warfarin is most commonly prescribed, and can also cause the development of systemic arterial plaque when cholesterol levels are normal.

There are no diagnostic tests on which all Sneddon's patients will have abnormal results, although brain MRI and skin biopsy are often abnormal. The diagnosis is based on a detailed history and physical examination. About 40 60% of patients with the syndrome test positive for antiphospholipid antibodies.

Sneddon's patients are generally treated with warfarin, maintaining a high INR of 3–4. In 1965, Dr. Sneddon first reported 6 patients with a distinct skin rash and cerebrovascular accidents (strokes). Sneddon's Syndrome was formerly understood to be a type of autoimmune disease called antiphospholipid syndrome, although it has been reclassified as a noninflammatory cerebrovascular disease. It should be considered in patients diagnosed with vasculitis when standard treatments fail.