scleroderma

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.

Types and variants

There are two main types of scleroderma: a systemic form known as progressive systemic scleroderma, which can be life-threatening, and a localized form, which is usually not as serious. Localized scleroderma mainly affects the skin and nearby tissues, appearing as thickened patches or bands of hardened skin. Systemic scleroderma, or systemic sclerosis, involves not only the skin but also internal organs, such as the lungs, heart, kidneys, and digestive tract.

Within systemic disease, there are limited forms, which progress gradually and often affect the hands, face, and forearms, and diffuse forms, which spread more quickly and may cause significant organ complications. Diffuse cutaneous systemic sclerosis (dcSSc), for instance, is a rapidly progressive form that involves widespread skin thickening, including of the trunk and proximal limbs, and tends to cause earlier and more severe internal organ involvement, particularly in the lungs, heart, and kidneys.

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The most common variant of progressive systemic scleroderma is limited cutaneous systemic sclerosis (lcSSc), or CREST syndrome. The acronym is derived from the first letters of the five main features of the disease:

• Calcinosis cutis, calcium deposits in the skin
• Raynaud phenomenon
• Esophageal dysfunction
• Sclerodactyly, tightening of the skin on the fingers and toes
• Telangiectasia, red spots on the face, lips, forearms, and hands

Symptoms and progression

The term scleroderma, which means “hard skin,” refers to 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 ages 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. Progressive systemic scleroderma may be particularly difficult to recognize, since early symptoms mimic many common autoimmune or rheumatic conditions. 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 color from pale to blue to red in response to cold or stress, a manifestation known as Raynaud syndrome (also called Raynaud phenomenon), which is characterized by spasms in the arteries (primarily of the fingers and toes) that drastically restrict blood flow. As the disease progresses, the facial skin often tightens into a shiny mask. Swelling may occur, initially in the fingers, hands, and feet, 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.

Causes

The signs and symptoms of scleroderma arise because the tissue of the targeted organ is inflamed and irritated and eventually becomes scarred and loses its 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 for the autoimmune response is not known. Some individuals appear to have a genetic predisposition that raises their risk of developing the condition. Exposure to certain environmental factors, including bacterial or viral infections or chemicals such as vinyl chloride or industrial solvents, may trigger the disease in susceptible individuals.

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Treatment

No cure has been found for scleroderma, but treatments are available that help alleviate its symptoms. For example, corticosteroids help reduce inflammation, and immunosuppressants can slow skin thickening. Heat, massage, moisturizers, and physical therapy are often of value, and sometimes a change of climate can bring about improvement.