Scleroderma is derived from the Greek words skleros (hard or indurated) and derma (skin). The two main classes are localized scleroderma and systemic sclerosis. Scleroderma is a systemic disease that affects many organ systems. It is most obvious in the skin; however, the gastrointestinal tract, the respiratory, renal, cardiovascular, and genitourinary systems, as well as numerous vascular structures, are involved frequently. The symptoms result from progressive tissue fibrosis and occlusion of the microvasculature by excessive production and deposition of types I and III collagens. Other macromolecules found in the connective tissue (eg, glycosaminoglycans, tenascin, fibronectin) also are increased.

A 3- to 8-times higher risk exists for women than men. The incidence for women peaks during childbearing years. The peak onset occurs in patients aged 30-40 years.

Limited scleroderma, also called CREST, is progressive and unremitting. It is classified as a systemic because its effects can be widespread. CREST is an acronym,whose letters are the first initials of characteristics that are typically found in this syndrome:

Pulmonary involvement in scleroderma occurs as diffuse interstitial lung disaease that is clinically, radiologically and histologically similar to idiopathic pulmonary fibrosis , or cryptogenic fibrosing alveolitis.

HRCT findings include ground glass opacities, septal lines,