Systemic Sclerosis A. Clinical Features

Systemic sclerosis (scleroderma; SSc) is divided further into limited cutaneous disease and diffuse cutaneous disease on the basis of the extent of skin thickening. Limited disease is defi ned as skin thickening that only affects the extremities below the elbows and/or below the knees. Diffuse cutaneous disease is defi ned as skin thickening proximal to the elbows/or knees in addition to distal extremity involvement. Truncal skin may also be involved in diffuse cutaneous systemic sclerosis (dcSSc). The face can be involved in both forms and has no bearing on subset designation. The clinical manifestations of SSc may be considered the result of three pathological processes: (1) a small vessel non-infl ammatory obliterative vasculopathy; (2) the pathological accumulation of collagen in skin and other organs (fi brosis); and (3) autoimmunity. The obliterative small vessel vasculopathy is responsible for Raynaud’s phenomenon, scleroderma renal crisis, and pulmonary artery hypertension. The fi brosing process results in thickened skin, pulmonary parenchymal disease, and gastrointestinal dysmotility. Tendon friction rubs, caused by an infl ammation in the tendon sheath, are usually palpable on examination and sometimes cause pain with motion. A variety of autoantibodies occur in SSc, including those anti–topoisomerase III antibodies and anticentromere antibodies. Raynaud’s phenomenon, usually the fi rst manifestation of SSc, may precede the development of other features by months to years. Pulmonary disease is now the leading cause of death in SSc. Pulmonary fi brosis occurs in many SSc patients, with 20% ultimately requiring supplemental oxygen. Scleroderma renal crisis, the most common cause of death in SSc prior to the introduction of angiotensinconverting enzyme (ACE) inhibitors, remains an important source of patient morbidity in SSc.