Localized types of scleroderma are those limited to the skin and surrounding tissues including, in some cases, the muscle below. Internal organs are not affected by localized scleroderma, and localized scleroderma does not progress to the systemic form of the disease. Often, localized conditions improve or go away on their own over time, but the skin changes and damage that occurs when the disease is active may be permanent. Localized scleroderma takes one of two forms: Morphea or Linear.
The first signs of the disease are reddish patches of skin that thicken into firm, oval-shaped areas. The center of each patch becomes ivory coloured with violet borders. These patches sweat very little and have little hair growth. Patches appear most often on the chest, stomach, and back. Sometimes they appear on the face, arms, and legs. Morphea can be either localized or generalized. Localized morphea limits itself to one or several patches, ranging in size from a half-inch to 12 inches in diameter. The condition sometimes appears on areas treated by radiation therapy. Some people have both morphea and linear scleroderma (described below). The disease is referred to as generalized morphea when the skin patches become very hard and dark and spread over larger areas of the body. Regardless of the type, morphea generally fades out in 3 to 5 years; however, people are often left with darkened skin patches and, in rare cases, muscle weakness.
As suggested by its name, the disease is characterized by a single line or band of thickened, unusually coloured skin. Typically, the line runs down an arm or leg, but in some people it runs down the forehead.