Morphea

Morphea is a localized form of scleroderma involving isolated patches of hardened, thickened skin, most often on the face, hands, and feet, though it can appear anywhere on the body, and it typically spares the internal organs, unlike systemic sclerosis, which can affect organs throughout the body; a deeper variant called deep morphea can extend into underlying fat, connective tissue, and sometimes bone. The thickened, hardened patches result from an overproduction of collagen in the skin, and lesions can appear as flat spots, raised plaques, bands, or nodules ranging from small areas to widespread involvement, with up to fifteen percent of patients showing a mix of these forms. Its exact cause is unknown, though the evidence points toward an autoimmune process, supported by a higher rate of family history of autoimmune disease and by specific autoantibodies found in many patients; infection with the bacterium Borrelia burgdorferi has also been linked to a distinct autoimmune form of the disease in younger patients. It is uncommon, affecting an estimated two to four people per hundred thousand, and occurs about three times more often in women than in men, in both children and adults.