scleroderma, a chronic disease of the skin that also can affect the blood vessels and various internal organs. Scleroderma is characterized by excessive deposition of collagen—the principal supportive protein of the connective tissues—in affected areas. There are two main types of scleroderma: a systemic form called progressive systemic scleroderma, which can be life-threatening, and a localized form, which is usually not as serious.
The term scleroderma, which means “hard skin,” indicates the hardening and thickening of the skin that is the most common feature of the disease. Scleroderma strikes women more often than men and may begin at any age, although symptoms commonly appear in persons between the ages of 25 and 50. In cases of localized scleroderma, isolated patches of hardened skin are often the only sign of the disease. Occasionally muscles and bone are involved, but no internal organs are affected. In cases of progressive systemic scleroderma, however, many parts of the body may be involved, including the skin, blood vessels, kidneys, lungs, heart, and gastrointestinal tract. The severity of systemic scleroderma depends on which organs are affected and to what degree they become damaged. Those with localized scleroderma do not usually develop systemic scleroderma.
The onset of progressive systemic scleroderma usually is marked by hands and feet changing colour from pale to blue to red in response to cold, a manifestation called Raynaud phenomenon that is caused by abnormal blood flow. As the disease progresses, the facial skin often tightens into a shiny mask. Swelling may occur, along with skin discoloration, numbness, and a tingling feeling. The course of the disease is variable and unpredictable. Sometimes years intervene between the early manifestations and the more serious signs of systemic involvement, which may include difficulty in breathing or swallowing, gastrointestinal disorders, kidney malfunction, and inflammation of the heart lining, heart muscle, or sac enclosing the heart. If heart, lung, or kidney dysfunction occurs early in the course of the disease, the prognosis is poor.
There is a milder variant of progressive systemic scleroderma, called CREST syndrome. The acronym is derived from the first letters of the five main features of the disease:
The signs and symptoms of scleroderma arise because the tissue of the targeted organ is inflamed and irritated and eventually becomes scarred and loses normal elasticity. These changes occur as a result of an increase in the deposition of collagen in the targeted areas. Collagen overproduction is thought to result from an autoimmune reaction—i.e., a malfunctioning of the immune system that causes the body to attack its own components. The stimulus that results in this derangement of the immune system is not known.
No cure has been found for scleroderma, but treatments are available that help alleviate its symptoms. For example, corticosteroids help reduce inflammation, and immunosuppressants and other drugs help soften the skin. Heat, massage, and physical therapy are often of value, and sometimes a change of climate can bring about improvement.