Sneddon Syndrome - Causes, Symptoms, and Treatment

Introduction:

Sneddon syndrome is a rare, chronic, slow, and episodic skin disease affecting blood vessels. Skin conditions, cerebrovascular events, and neurological abnormalities characterize it. The characteristic findings include skin discoloration, stroke, and multiple episodes of reduced blood flow to the brain. The central nervous system (CNS) part of the brain is mainly affected by reduced blood flow, and lesions develop within the CNS, causing dizziness, headache, heart disease, memory loss, high blood pressure, and neurological symptoms. The cause of the condition needs to be better understood. The focus of the treatment is to manage symptoms and prevent complications. The article discusses Sneddon syndrome, its causes, symptoms, diagnosis, treatment, and complications.

What Is Sneddon Syndrome?

Sneddon syndrome is a rare genetic disorder that affects blood vessels. Endothelial cells line the blood vessels, and the growth is too quick, causing blood flow issues. Ian Bruce Sneddon first described Sneddon syndrome in 1965. At that time, the debate existed about whether Sneddon syndrome was a subtype of antiphospholipid syndrome. Some scientists believe that it is classified into primary and secondary. Primary Sneddon syndrome is a case in which the syndrome's cause is unknown. Secondary Sneddon syndrome is a case that occurs secondary to other disorders. It is also called a thrombophilic state. Sneddon syndrome is an autoimmune disease associated with some autoimmune diseases, such as systemic lupus erythematosus (the immune system attacks its healthy cells) and antiphospholipid syndrome (the formation of abnormal blood clots).

Women are more commonly affected than men. Around 80 percent of women are affected by the condition. The average age of affected people is around 40 years. The condition's incidence is approximately one million per year in the general population. The racial variation does not appear.

The other names of Sneddon syndrome are as follows:

• Sneddon-Champion syndrome.

• Livedo racemosa-cerebrovascular accident syndrome.

• Livedo reticularis-cerebrovascular accident syndrome.

• Ehrmann-Sneddon syndrome.

What Are the Causes of Sneddon Syndrome?

The causes of Sneddon syndrome are not completely understood. Due to its genetic component, the condition is repeated in families. Changes in the CECR1 gene can cause the condition. This gene helps produce an enzyme called adenosine deaminase 2, which protects and supports the blood vessel lining.

The condition is associated with antiphospholipid syndrome, and antiphospholipid antibody markers are found in around 50 to 80 percent of patients with Sneddon syndrome. The skin and brain's small and medium-sized blood vessels are affected, causing coagulopathy (impairment of blood clot formation) and thrombophilia (quick formation of blood clots). It decreases activated C protein and protein S (glycoprotein synthesized in the liver) and increases factor VII (vitamin K-dependent factor involved in coagulation).

What Are the Risk Factors for Sneddon Syndrome?

The risk factors for Sneddon syndrome are as follows:

• Oral contraceptives.

• Reproductive hormones.

• High blood pressure.

• Autoimmune diseases.

• Women are at more risk.

• Blood clotting disorders, such as thrombophilia.

• Previous vascular events, such as a history of strokes (stoppage of blood flow to the brain) or transient ischemic attacks (temporary brain blood flow blockage).

• Immune system abnormalities.

• Antiphospholipid antibodies which are linked to abnormal blood clotting.

What Are the Signs and Symptoms of Sneddon Syndrome?

Sneddon syndrome mainly affects the skin, the brain, and the heart. The dermatological and neurological manifestations of Sneddon syndrome are as follows:

Dermatological Manifestations:

The initial dermatological symptom is the livedo racemosa, which affects the child, and the symptom is recognized at the age of 20 to 30 years. The dermatological manifestations of Sneddon syndrome are as follows:

• Livedo Racemosa: Livedo racemosa is a mottled skin discoloration that presents as a net, lace, or branch-like pattern of erythematous broken circles with pale central skin. It occurs due to blockage of peripheral blood flow due to the obstruction of small and medium-sized arteries. The lower back, buttocks, and lower extremities are usually affected, and the lesion progresses to involve the arms and thighs. The face and hands are rarely affected. The lesion is usually painless and is not associated with swelling or ulceration.

• Livedo Reticularis: It is a bluish-purple skin discoloration with net-like mottling of the skin. It mainly affects the lower extremities. However, the condition worsens during the cold weather and goes away when the affected person is in the warmer season.

• Sudden numbness or weakness of the face, leg, and arm.

Neurological Manifestations: The three stages associated with Sneddon syndrome are as follows:

• Prodromal Symptoms: The symptoms include dizziness, vertigo (dizziness), and headaches.

• Second Stage: During this stage, the patient experiences repeated episodes of strokes,and transient ischemic attacks occur due to ischemia. The symptoms include visual field defects, sensory disturbances, aphasia (language disorder causing difficulty in communication), and hemiparesis (muscle weakness on one side).

• Third Stage: It is characterized by dementia (impaired thinking and interference in making decisions) and cognitive decline. The cognitive impairment causes dysfunction, such as memory loss, difficulty in attention, change in behavior, depression, and psychiatric disturbances.

Cerebrovascular Manifestations: The cerebrovascular symptoms are as follows:

• Ischaemic stroke.

• Seizures.

• Hemorrhagic stroke.

• Movement disorder.

How Is Sneddon Syndrome Diagnosed?

The diagnosis of Sneddon syndrome is described below:

• Physical Examination: The healthcare provider may physically examine the patient and review the patient's medical history and symptoms. The doctor may see blood to check for blood clotting issues, the heart to check blood flow in the heart and blood vessels, the brain to look for damage, and skin for changes in the skin color.

• Imaging Tests: The healthcare provider may recommend imaging tests, such as magnetic resonance imaging (MRI) and computed tomography (CT), to diagnose the condition. These tests are used to visualize stroke-related damage in the brain.

• Echocardiography: The healthcare provider will perform echocardiography to examine the blood vessels and heart.

• Skin Biopsy: This is performed to check for skin abnormality. The sample is taken from the livedo reticularis area and examined under a microscope for changes in the blood vessels.

How Is Sneddon Syndrome Treated?

The main aim of the treatment is to manage symptoms through lifestyle modification and medications. The treatment of Sneddon syndrome is as follows:

• Blood Thinning Medications: These are also known as anticoagulant medications, generally prescribed to reduce the risk of stroke.

• Vasodilators: Vasodilators, such as Nifedipine, are prescribed to increase blood flow. This will relieve skin symptoms.

• Angiotensin-Converting Enzyme Inhibitors: These are prescribed to stop endothelial cell growth.

• Lifestyle Modifications: Lifestyle changes include cessation of smoking and avoiding estrogen-containing oral contraceptives.

What Are the Complications of Sneddon Syndrome?

The complications of Sneddon syndrome are as follows:

• Hypertension.

• Macular edema (leakage of blood vessels into the retina).

• Retinal artery branch obstruction (blocked retinal artery).

• Renal artery thrombosis (obstruction of retinal blood flow).

• Impaired creatinine clearance (kidney damage).

Conclusion:

Sneddon syndrome is a rare hereditary condition affecting the blood vessels of the skin and brain. It causes lace, net-like, and mottled skin discoloration, affecting the buttocks, thighs, and lower extremities. It is diagnosed through skin biopsy and imaging tests. Anticoagulant medications, vasodilators, and lifestyle changes help manage the condition. People should stop taking oral-contraceptive pills and avoid smoking to manage associated symptoms. If an individual experiences skin discoloration, they should contact a dermatologist for early diagnosis and treatment and to prevent complications.