Scleroderma literally means hard skin, but the damage starts in blood vessels
Scleroderma is a family of autoimmune diseases in which connective tissue overgrows, leaving skin thick, hard and ivory-smooth. The leading theory places the first injury in the lining of small blood vessels. About three people per 100,000 develop the systemic form each year, most often women in middle age.
The name joins the Greek words for hard and skin. Carlo Curzio described the symptoms in 1753, and fuller accounts followed in 1842. Some forms stay confined to the skin; others reach the lungs, gut, heart and kidneys. A limited variant known as CREST syndrome bundles calcium deposits, Raynaud's syndrome, oesophageal trouble, thickened skin on the fingers and toes, and clusters of tiny dilated vessels.
Raynaud's phenomenon, in which fingers and toes lose blood flow in the cold, is the first sign in about 30% of patients and appears in 95% at some point. The proposed sequence runs like this: something, perhaps a virus, oxidative stress or an autoimmune attack, injures the endothelial cells lining small vessels. The damaged lining leaks, fails to repair properly and tilts towards constriction. Immune cells are drawn in, antibodies form against proteins such as topoisomerase I, and fibroblasts turn into myofibroblasts that pour out collagen, producing the scarring called fibrosis. Low vitamin D levels track with more severe disease.
The cause remains unknown. Family history and certain genes, notably HLA variants, raise risk, and a minority of cases are linked to exposure to silica, solvents such as trichloroethylene, or welding fumes. There is no single reliable test. Doctors look for symmetrical skin thickening and specific antibodies, and in patients without those antibodies, magnified views of the capillaries at the nail fold can reveal enlarged or missing vessels.
No cure exists, but many complications can be treated individually, from the circulation problems in the fingers to lung disease and kidney crises, and immunosuppressant drugs are commonly used to slow the disease overall. Localised disease rarely shortens life. As of 2012, about 85% of people with the systemic form survived five years and just under 70% survived ten, with the diffuse type faring worse than the limited one; lung complications and kidney crisis are the main threats.
Source: Scleroderma
