Sneddon Syndrome

National Organization for Rare Disorders, Inc.

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It is possible that the main title of the report Sneddon Syndrome is not the name you expected.

Disorder Subdivisions

  • None

General Discussion

Sneddon syndrome is a rare progressive disorder affecting small- and medium-sized blood vessels. The disorder is characterized by the association of a skin condition and neurological abnormalities. Characteristic findings include multiple episodes of reduced blood flow to the brain (cerebral ischemia) causing mini-strokes or stroke and bluish net-like patterns of discoloration on the skin surrounding normal-appearing skin (livedo reticularis). Additional symptoms may include headache, dizziness, abnormally high blood pressure (hypertension), and heart disease. Lesions may develop within the central nervous system as a result of reduced blood flow to the brain, which can cause reduced intellectual ability, memory loss, personality changes, and/or other neurological symptoms. The combination of stroke symptoms and livedo reticularis differentiates this syndrome from other disorders. The exact cause of Sneddon syndrome is not fully understood.

Sneddon syndrome was first described a separate clinical entity in the medical literature by Dr. Sneddon and colleagues in 1965. Since that time, significant debate has existed as to whether Sneddon syndrome is a distinct disorder, part of a spectrum of disorders, or a subtype of antiphospholipid syndrome. Some researchers believe that Sneddon syndrome should be separated into primary and secondary cases. Primary Sneddon syndrome would denote cases where there was no known cause (idiopathic); secondary Sneddon syndrome would denote cases that are believed to occur secondary to another disorder or thrombophilic state. Some researchers believe that Sneddon syndrome should be differentiated by whether antiphospholipid antibodies are present (aPL-positive) or absent (aPL-negative).

Supporting Organizations

Genetic and Rare Diseases (GARD) Information Center

PO Box 8126
Gaithersburg, MD 20898-8126
Tel: (301)251-4925
Fax: (301)251-4911
Tel: (888)205-2311

NIH/National Heart, Lung and Blood Institute

P.O. Box 30105
Bethesda, MD 20892-0105
Tel: (301)592-8573
Fax: (301)251-1223

NIH/National Institute of Neurological Disorders and Stroke

P.O. Box 5801
Bethesda, MD 20824
Tel: (301)496-5751
Fax: (301)402-2186
Tel: (800)352-9424

National Stroke Association

9707 E. Easter Lane
Suite B
Centennial, CO 80112
Tel: (303)649-9299
Fax: (303)649-1328
Tel: (800)787-6537

For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders (NORD). For a full-text version of this report, go to and click on Rare Disease Database under "Rare Disease Information".

The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only.

It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report.

This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.

Last Updated:  1/8/2016
Copyright  2016 National Organization for Rare Disorders, Inc.