With an estimated 14 million cases worldwide, you would think more would be known about scleroderma, a chronic, debilitating disease that can lead to the hardening and tightening of skin and connective tissue. But it seems that we don’t know enough: “We don’t have all the answers and that is the reason why we need to do more research,” says Carol Feghali-Bostwik, Ph.D., assistant professor of medicine at the University of Pittsburgh.

What we do know is that scleroderma is at least three times more common in women than in men, according to the National Institutes of Health. The cause remains unknown. The incidence peaks between the ages of 35 and 54 and the disease course varies greatly from person to person. For some people, the disease remains local and mostly affects the skin of the face and hands, causing it to tighten and thicken. For others, the disease is systemic and more severe, affecting the skin and other organs including the kidneys, gastrointestinal tract, heart, lung and joints. In these areas, it can cause damaging fibrosis, which is the abnormal formation or development of excess fibrous connective tissue in an organ or tissue.

Like other autoimmune diseases, scleroderma seems to hit women harder. “We don't quite know why it’s more frequent in women but believe that hormonal influences may be responsible for the female preponderance,” Feghali-Bostwik said. “There is evidence from animal studies that estrogens play a role in the development of fibrosis.”