The changes, which occur in localized scleroderma, are usually found in only a few places on the skin or muscles, and rarely spread elsewhere. Generally, localized scleroderma is relatively mild. The internal organs are usually not affected, and persons with localized scleroderma rarely develop systemic scleroderma. Some laboratory abnormalities commonly seen in systemic scleroderma are frequently absent in the localized form.
Morphea is a form of localized scleroderma characterized by waxy patches on the skin of varying sizes, shapes and color. The skin under the patches may thicken. The patches may enlarge or shrink, and often may disappear spontaneously. Morphea usually appears between the ages of 20 and 50, but is often seen in young children.
Linear scleroderma is a form of localized scleroderma which frequently starts as a streak or line of hardened, waxy skin on an arm or leg or on the forehead. Sometimes it forms a long crease on the head or neck, referred to as en coup de sabre because it resembles a saber or sword wound. Linear scleroderma tends to involve deeper layers of the skin as well as the surface layers, and sometimes affects the motion of the joints which lie underneath. Linear scleroderma usually develops in childhood. In children, the growth of involved limbs may be affected.