Scleroderma is a rare disease of the connective tissue. It can cause the tissue in skin, joints, and internal organs to thicken and stiffen. There are three major forms of the disease:

  • Localized scleroderma (also known as morphea)—usually affects only the skin in isolated parts of the body. This form is less serious.
  • Systemic scleroderma—affects widespread areas of skin and/or internal organs, most often the lungs (Certain categories of this form of scleroderma are more serious and can be fatal.)
  • Overlap syndrome—may involve features of scleroderma and features of other autoimmune syndromes

Overproduction of collagen and other connective tissue proteins is the main feature of scleroderma. It is not clear what causes this overproduction. Malfunction of the immune system may contribute to excess collagen production. There is also evidence that scleroderma may result from vascular abnormalities.