What is scleroderma?
Scleroderma is a group of connective tissue disorders with similar symptoms. They are associated with thickened, hardened skin, fibrosis, inflammation, blood vessel degeneration, and tissue damage. Scleroderma may be localized or systemic. It may be confined to patches of skin on the trunk, face, or extremities, or may affect large areas of the body, penetrating deep into muscle, bone, and internal organs such as the heart, lungs, gastrointestinal tract, and kidneys. Symptoms may range from cosmetic concerns to tissue damage and from pain and a decreased ability to move and use the hands to life-threatening kidney or lung dysfunction.
Localized scleroderma affects the skin and, in some cases, the muscle beneath it. There are two general types: morphea and linear scleroderma.
- Morphea is associated with firm, thickened, discolored oval patches of skin on the chest, back, legs, arms, or face. The patches may be reddened or white with a purplish border and may appear singly or cover large areas.
- Linear scleroderma appears as a line or band of thickened tissue. If it forms over a child's joint, it may limit joint development and mobility.
Systemic scleroderma can be categorized as either limited cutaneous scleroderma or diffuse cutaneous scleroderma.
- Limited cutaneous scleroderma typically affects specific areas of the body and may be referred to as "CREST," an acronym for the most common symptoms (see Signs & Symptoms).
- Diffuse cutaneous scleroderma is widespread. It can affect the skin and cause dysfunction in systems and organs throughout the body.
Scleroderma is relatively rare and its prevalence is somewhat difficult to determine. It is estimated that there are about 240 cases for every million people, with about 19 new cases per million people each year. Scleroderma is inflammatory and appears to have an autoimmune component, but the exact cause of the related disorders is not yet known. They can affect anyone at any age, but most cases are seen in those who are 20 to 40 years old. Women of child-bearing age are affected four times more often than men, so it is suspected that the disorders also have a hormonal component. Although a predisposition is not directly inherited, there are some increased frequencies of scleroderma tied to ethnicity. Localized scleroderma is more common in those of European descent, while systemic scleroderma affects more women of African descent. Scleroderma-like disorders are seen with exposures to chemicals such as vinyl chloride, trichloroethylene, and contaminated rapeseed oil, but scleroderma itself has not been tied to an environmental trigger.