The different forms of Scleroderma
Scleroderma is generally divided into two main forms: localized scleroderma and systemic scleroderma (or systemic sclerosis).
Localized scleroderma (or morphea)
Localized scleroderma is a fibrotic disease of the skin and sometimes of the underlying tissues, but does not affect internal organs. It affects mostly children, but can also occur in adulthood. There are several forms of localized scleroderma, including circumscribed or plaque morphea (involving one or multiple well-defined, oval to round areas of skin thickening), generalized morphea (when at least 4 plaques involving at least 2 anatomical sites are present), linear scleroderma (characterized by tight, thick bands, frequently affecting extremities) and scleroderma en coup de sabre (a type of linear scleroderma that affects the forehead and scalp area on one side of the head, with resemblance to the cut of a saber).
Systemic sclerosis: limited or diffuse
In contrast, systemic sclerosis (or systemic scleroderma) is a fibrotic skin disease that can also affect internal organs (hence the term “systemic”). When fibrotic skin involvement is limited to the hands, forearms, feet, legs below the knees, face and/ or neck, it is referred to as limited systemic sclerosis. When the skin involvement goes up above the elbows and knees, affecting the skin of the upper arms, thighs, trunk and/or abdomen, it is then referred to as diffuse systemic sclerosis. Involvement of the skin and internal organs is generally more common and extensive in the diffuse form of systemic sclerosis.