This multicenter study will attempt to determine the epidemiologic, clinical, serologic and immunogenetic factors associated with patients who develop scleroderma/systemic sclerosis after silicone prosthesis implantation or silicone injection. This will be accomplished by comparing these patients to groups of appropriately matched patients with idiopathic scleroderma/systemic sclerosis without silicone exposure, and appropriately matched volunteers who have received similar silicone implants or injections and have not developed symptoms, physical examination findings, or laboratory abnormalities associated with autoimmune/connective tissue diseases. Patient and physician questionnaires will be self-administered, and will collect data regarding: the number and types of implanted silicone devices or injections; the indications for and nature of the surgical procedures; peri- and post-operative complications; initial and subsequent clinical presentations; and therapy and clinical course of the patients. Routine clinical tests and immunologic laboratory evaluations will be performed. Also, studies will be conducted on the proportion of circulating activated lymphocytes and levels of soluble mediators of inflammation (cytokines, sIL-2R, sCD4, sCD8, TNF), the types of HLA and T cell receptor genes present in the patients, and the presence and titers of anti-silicone antibodies and autoantibodies.