Childhood-type myositis and linear scleroderma.

A 5-year-old girl had linear scleroderma on the flexor surface of the right arm; muscle wasting included the shoulder girdle. IgM fluorescence on blood vessels and along dermal-epidermal junction was observed by direct immunofluorescence in biopsied skin. Biceps muscle underlying the plaque of the scleroderma showed atrophy of entire fascicles, perifascicular atrophy, and cellular infiltration around blood vessels that are quite similar to those found in childhood-type dermatomyositis. In addition, various abnormalities, including edema and thickening of basal lamina, were found on blood vessels in muscle tissue. The results suggested that the autoimmune collagen vascular disorder is responsible for this condition.