[Scleroderma, dermatomyositis].

Systemic sclerosis (scleroderma, SSc) is a progressive and often fatal disorder characterized clinically by sclerotic changes in the skin, joints and internal organ systems such as the gastrointestinal tract, heart, lungs and kidneys, moreover pathologically by abnormalities of mucopolysaccharides, fibrous tissue deposition, atrophy of parenchymal structures in skin and various internal organs, and by vascular insufficiency. Little is known of its etiology and pathogenesis. Transforming growth factor-beta (TGF-beta), platelet derived growth factor-AA (PDGF-AA) and PDGF-alpha receptor interaction may play an important role in the pathogenesis of scleroderma. Furthermore, many of the proteoglycans act as modulators of growth factor activities. Dermatomyositis is also a complex connective tissue disease of unknown etiology, in which inflammatory change in the skin, muscle, and lung in association with vascular insufficiency and internal malignancy.