Section 5. Bone, Joint, and Muscle Disorders

Chapter 68. Autoimmune Disorders of Connective Tissue

Topics: Introduction | Systemic Lupus Erythematosus | Scleroderma | Sjögren's Syndrome | Polymyositis and Dermatomyositis | Mixed Connective Tissue Disease | Relapsing Polychondritis | Eosinophilic Fasciitis

Scleroderma

Scleroderma (systemic sclerosis) is a chronic disorder characterized by degenerative changes and scarring in the skin, joints, and internal organs and by blood vessel abnormalities.

The cause of scleroderma is not known. The disorder is 4 times more common in women than in men and is rare in children. Symptoms of scleroderma may occur as part of mixed connective tissue disease, and some people with mixed connective tissue disease develop severe scleroderma.

Symptoms

The usual initial symptom of scleroderma is swelling, then thickening and tightening of the skin at the ends of the fingers. Raynaud's phenomenon, in which the fingers suddenly become very pale and tingle or become numb and/or painful in response to cold or emotional upset (see Section 3, Chapter 34) is also common. Fingers typically become bluish as they warm up. Heartburn, difficulty in swallowing, and shortness of breath are occasionally the first symptoms of scleroderma. Aches and pains in several joints often accompany early symptoms. Sometimes polymyositis, with its accompanying muscle pain and weakness, develops.

Scleroderma can damage large areas of skin or only the fingers (sclerodactyly). One form of scleroderma, called limited scleroderma, tends to stay restricted to the skin of the hands. In another form, called diffuse scleroderma, the disorder progresses; the skin becomes more widely taut, shiny, and darker than usual. The skin on the face tightens, sometimes resulting in an inability to change facial expressions. Especially in the limited form, spider veins (telangiectasia) can appear on the fingers, chest, face, lips, and tongue; bumps composed of calcium can develop on the fingers, on other bony areas, or at the joints.

Sometimes, a grating sound can be felt or heard as inflamed tissues move over each other, particularly at and below the knees. The fingers, wrists, and elbows may freeze (forming a contracture) in flexed positions because of scarring in the skin. Sores can develop on the fingertips and knuckles.

Scarring commonly damages the lower end of the esophagus (the tube connecting the mouth and stomach). The damaged esophagus can no longer propel food to the stomach efficiently. Swallowing difficulties and heartburn eventually develop in most people who have scleroderma. Abnormal cell growth in the esophagus (Barrett's esophagus (see Section 9, Chapter 131)) occurs in about one third of the people, increasing their risk of esophageal blockage (stricture) due to a fibrous band or to cancer. Damage to the intestines can interfere with food absorption (malabsorption) and cause weight loss. The drainage system from the liver may become blocked by scar tissue (biliary cirrhosis), resulting in liver damage and jaundice.

Scleroderma can cause scar tissue to accumulate in the lungs, resulting in abnormal shortness of breath during exercise. It can also cause several life-threatening heart abnormalities, including heart failure and abnormal rhythms.

Severe kidney disease can result from scleroderma. The first symptom of kidney damage may be an abrupt, progressive rise in blood pressure. High blood pressure is an ominous sign, although treatment usually controls it.

The CREST syndrome, also called limited cutaneous scleroderma (sclerosis) is usually a less severe form of the disorder that is less likely to cause serious internal organ damage. It is named for its symptoms: Calcium deposits in the skin and throughout the body, Raynaud's phenomenon, Esophageal dysfunction, Sclerodactyly (skin damage on the fingers), and Telangiectasia (spider veins). Skin damage is limited to the fingers. People who have the CREST syndrome can develop pulmonary hypertension (see Section 4, Chapter 54), which can cause heart and lung failure.

Sometimes scleroderma worsens rapidly and becomes fatal. At other times, it affects only the skin for decades before affecting internal organs, although some damage to internal organs (such as the esophagus) is almost inevitable, even in the CREST syndrome.

Diagnosis

A doctor diagnoses scleroderma by the characteristic changes in the skin and internal organs. The symptoms may overlap with those of several other connective tissue disorders, but the whole pattern is usually distinctive. Laboratory tests alone cannot identify scleroderma because test results, like the symptoms, vary greatly. However, tests for an antibody to centromeres (part of a chromosome) may help distinguish limited cutaneous scleroderma from the more generalized form; the more generalized form may contain a different antibody (called anti-topoisomerase).

Prognosis and Treatment

The course of scleroderma varies and is unpredictable, sometimes being fatal. The prognosis is worst for those who have early symptoms of heart, lung, or kidney damage.

No drug can stop the progression of scleroderma. However, drugs can relieve some symptoms and reduce organ damage. Nonsteroidal anti-inflammatory drugs (NSAIDs) (see Section 6, Chapter 78) help relieve severe muscle and joint pain. If the person has weakness because of polymyositis, corticosteroids may be needed. Penicillamine is thought by some experts to slow the rate of skin thickening and may delay the involvement of additional internal organs, but this use is controversial and some people cannot tolerate the side effects of this drug. Drugs that suppress the immune system, such as cyclophosphamide and methotrexate, may help some people whose lungs are affected.

Heartburn can be relieved by eating small meals and taking antacids, histamine-blocking drugs, and proton pump inhibitors, which block stomach acid production. Sleeping with the head of the bed elevated often helps. Surgery can sometimes correct severe reflux of stomach acid. Areas of the esophagus narrowed by scar tissue can be surgically widened (dilated). Tetracycline or other antibiotics can help prevent malabsorption of food caused by excessive growth (overgrowth) of bacteria in the damaged intestine. Nifedipine or an angiotensin II receptor blocker may relieve the symptoms of Raynaud's phenomenon (see Section 3, Chapter 34) but may also increase the reflux of stomach acid. Drugs for high blood pressure, particularly angiotensin-converting enzyme (ACE) inhibitors, are useful in treating kidney disease and the rise in blood pressure.

Physical therapy and exercise can help to maintain muscle strength but cannot totally prevent joints from freezing in permanent (usually flexed) positions (contractures).