Sneddon-Syndrom

Synonym: Ehrmann-Sneddon syndrome

What is Sneddon's syndrome?

Sneddon's syndrome is a non-inflammatory arteriopathy in which livedo reticularis is associated with cerebrovascular disease.¹ It is slowly progressive and may go undiagnosed for some time.² It may be seen in patients with an autoimmune disorder - eg, Antiphospholipid-Syndrom oder systemischer Lupus erythematodes (SLE).

• It has been estimated that the incidence is 4 per 1 million per annum and generally occurs in women between the ages of 20 and 42 years.³

• Although initially thought to have a genetic aetiology (one family cluster displayed autosomal dominant inheritance), further studies have failed to demonstrate any family history in most affected patients.¹

• Sneddon's syndrome develops slowly over a variable timeframe.

• Livedo reticularis may precede the onset of stroke by years and the trunk and/or buttocks are involved in nearly all patients. The cerebrovascular manifestations are mostly secondary to ischaemia (transient ischemic attacks und cerebral infarction).

• Other neurological symptoms range from headache, cerebral haemorrhage, seizures, as well as cognitive and psychiatric disturbances.

• Involvement of fundi, peripheral nerves, heart, and kidneys is frequent but usually asymptomatic.

• Livedo reticularis is a bluish mottling of skin, usually on the legs, and the appearance may be aggravated by exposure to cold.⁴

• Sneddon's syndrome has been classified as primary if there is no clear cause, or secondary where it occurs as part of an autoimmune disorder (eg, Polyarteriitis nodosa, SLE, Antiphospholipid-Syndrom), or in a thrombophilic state (eg, thrombocythaemia).^{5 6}

• Other associations include hypertension, systemic ischaemia (including ischaemic heart disease), heart valve lesions and venous thrombosis.

• Antiphospholipid antibodies have been found in 80% of patients with Sneddon's syndrome.⁷

• Neuroimaging, including MRI, histological, immunohistochemical and ultrasound evaluation may be useful for diagnosis.⁸

• Histological findings of skin biopsies are characteristic and the involved vessels are small to medium-sized arteries at the border of dermis.³

• The optimal management remains uncertain. Long-term anticoagulation has been recommended for cerebral ischaemic events.³

• In patients without any prior history of thromboembolism, minimise risk factors (stop smoking and/or combined oral contraceptives, control any hypertension, and treat any hyperlipidaemia).

• Consider prophylaxis with low-dose aspirin (clopidogrel if unable to take aspirin), particularly in patients with antiphospholipid or antiprothrombin antibodies. It may be appropriate for all patients but more research is needed.

• Patients with a history of thrombosis are treated indefinitely with anticoagulation (with warfarin ± low-dose aspirin).

• Immunosuppressive agents are used in some cases chronically resistant to anticoagulation treatment.

• Some symptoms tend to resolve over a very variable time course.

• Prevention of further vascular events with anticoagulation is the key to a good prognosis.