Health Topics A-Z

What Is Scleroderma?

Scleroderma (pronounced SKLEER-oh-der-ma) is Greek for hard skin. It's classified as both a connective-tissue disorder and a rheumatic condition. In scleroderma, the skin gradually tightens and thickens or hardens. It loses its ability to stretch. Tiny blood vessels throughout the body also may be affected, causing widespread damage to the internal organs.

Although the disease usually affects the hands, face, and feet, impaired blood flow can eventually injure the body's digestive, respiratory, and circulatory systems.

Scleroderma can look very different in different people. There are many subtypes of this condition. Doctors generally classify scleroderma as either localized or systemic, depending on the degree to which the skin is affected. The widespread form of the disease is often called systemic sclerosis. It can be life threatening.

An estimated 300,000 Americans have scleroderma. The incidence varies across geographic regions, and appears to be higher in the U.S. than in Europe or Japan. No one race or ethnic group is affected more than another.

Women are affected in much greater numbers; they develop localized forms of the disease three times as frequently as men. More than 80% of people with systemic scleroderma are women aged 30 to 50. Rarely, children can also develop scleroderma. In the past two decades, longevity has improved for people with systemic scleroderma. Although scleroderma can be serious, most people live a normal life span with varying degrees of discomfort and/or disability.

What Causes It?

The underlying cause of scleroderma remains unclear. The main feature of the disease is excessive production of collagen. Collagen is one of the building blocks from which skin is made. Usually it makes the skin supple. But when too much collagen accumulates it causes various tissues to become thick and to lose flexibility. For some unknown reason, the immune system turns against the body, producing inflammation and the overproduction of collagen. Current research focuses on the interplay between the immune system, the vascular (blood vessel) system, and the growth of connective tissue. Studies with twins suggest it is not inherited.