Sneddon's syndrome

Sneddon's syndrome is a progressive, noninflammatory arteriopathy characterized by severe transient neurological symptoms or stroke together with a skin rash called livedo reticularis, a bluish-purple netlike mottling of the skin, or the larger-patched livedo racemosa. The skin signs usually appear first, often in the extremities and worse in the cold, and may precede neurological problems by years. Other features can include transient amnesia, transient aphasia, headaches, hypertension, transient ischemic attacks, coronary disease and, late in the course, dementia. It is named for Ian Bruce Sneddon, who in 1965 reported six patients with this rash and cerebrovascular accidents. It was formerly regarded as a form of antiphospholipid syndrome but has been reclassified as a noninflammatory cerebrovascular disease, although about 40 to 60 percent of patients test positive for antiphospholipid antibodies. No single test is abnormal in every patient, though brain MRI and skin biopsy often are, and diagnosis rests on history and examination. Patients are generally treated with warfarin at a high INR of 3 to 4. It is rare, usually misdiagnosed, most often apparent in women in their thirties, and may be inherited in an autosomal dominant fashion. This entry records what is documented and is not medical advice.