Raynaud's Syndrome Health Article

Definition

Raynaud's syndrome is a disorder in which the fingers or toes (digits) suddenly experience decreased blood circulation. It is also called Raynaud's disease.

Description

Raynaud's syndrome can be classified as one of two types: primary, or idiopathic (of unknown cause) disease; and secondary, which is also called Raynaud's phenomenon.

Primary Raynaud's disease is milder and causes fewer complications. About half of all cases of Raynaud's disease are of this type. Women are four times more likely than men to develop primary Raynaud's disease, and the average age of diagnosis is between 20 and 40 years. About 30% of all cases of primary Raynaud's disease progress after diagnosis, while 15% of cases actually improve.

Secondary Raynaud's disease is more complicated, severe, and more likely to get worse over time. A number of medical conditions or other triggers predispose a person to secondary Raynaud's disease, but do not directly cause the disorder. These include:

• Scleroderma. Scleroderma is a serious disease of the connective tissue, in which tissues of the skin, heart, esophagus, kidney, and lung become thickened, hard, and constricted. About 30% of patients diagnosed with scleroderma will then develop Raynaud's disease.
• Other diseases of connective tissue. These include systemic lupus erythematosus, rheumatoid arthritis, dermatomyositis, and polymyositis.
• Diseases that cause arterial blockage. These include atherosclerosis or hardening of the arteries.
• A severe form of high blood pressure which is caused by diseased arteries in the lung, called pulmonary hypertension.
• Disorders of the nervous system. These include herniated discs in the spine, strokes, tumors within the spinal cord, polio, and carpal tunnel syndrome.
• Other blood disorders.
• Trauma. Injuries that lead to Raynaud's are typically caused by exposure to constant vibration (workers who use chainsaws, jackhammers, or other vibrating equipment); repetitive movements (keyboard instrumentalists, assembly line workers, typists); electric shock; repeated use of the lower side of the palm as a hammer; or extreme cold (frostbite).
• Environmental toxins. Workers in the plastics industry who are exposed to high levels of vinyl chloride may develop a scleroderma-like illness that includes Raynaud's syndrome.
• Prescription medications. Drugs that increase the risk of developing Raynaud's include those used for migraine headaches or high blood pressure, and some cancer chemotherapy agents. Cases have also been reported of Raynaud's disease developing in reaction to quinine.

Causes

Both primary and secondary types of Raynaud's symptoms are believed to be due to overreactive arterioles, or small arteries. While cold normally causes the muscle which makes up the walls of arteries to contract (squeeze down to become smaller), in Raynaud's disease the degree is extreme. Blood flow to the area is severely restricted. Some attacks may also be brought on or worsened by anxiety or emotional distress.

Although the cause of primary Raynaud's is not known as of 2002, researchers are focusing on

prostaglandin metabolism and the function of endothelial cells in the body. Prostaglandins are a group of unsaturated fatty acids involved in the contraction of smooth muscle and the control of inflammation and body temperature. Endothelial cells form the layer of smooth tissue that lines the inside of the heart, blood vessels, and other body cavities.

Recent advances in gene mapping and sequencing indicate that Raynaud's may be linked to abnormal forms of a gene known as the Fibrillin-1 gene. This gene affects the composition of the protein molecules in human connective tissue.

Symptoms

Classically, there are three distinct phases to an episode of Raynaud's symptoms. When first exposed to cold, the arteries respond by contracting intensely. The digits in question, or in rare instances, the tip of the nose or tongue, become pale and white as they are deprived of blood flow and the oxygen carried by the blood. In response, the veins and capillaries dilate, or expand. Because these vessels carry deoxygenated blood, the digit becomes cyanotic, which means that it turns blue. The digit often feels cold, numb, and tingly. After the digit begins to warm up again, the arteries dilate. Blood flow increases significantly, and the digits turn a bright red. During this phase, the patient often describes the digits as feeling warm, and throbbing painfully.

Raynaud's disease may initially only affect the tips of the fingers or toes. When the disease progresses, it may eventually affect the entire finger or toe. Ultimately, all the fingers or toes may be affected. About 10% of the time, a complication called sclerodactyly may occur. In sclerodactyly, the skin over the affected digits becomes tight, white, thick, smooth, and shiny.

When the most serious complications of Raynaud's disease or phenomenon occur, the affected digits develop deep sores, or ulcers, in the skin. The tissue may even die, thus becoming gangrenous, and requiring amputation. This complication occurs only about 1% of the time in primary Raynaud's disease.