According to Wikipedia (edited Aug 2017), "Systemic scleroderma, also called diffuse scleroderma or systemic sclerosis, is an autoimmune disease of the connective tissue. It is characterized by thickening of the skin caused by accumulation of collagen, and by injuries to small arteries. There are two forms of scleroderma: localized and systemic. The localized (limited) form affects the skin of only the face, hands, and feet. The systemic (diffuse) form involves those and, in addition, may progress to visceral organs, including the kidneys, heart, lungs, and gastrointestinal tract."