Linear scleroderma along Blaschko's lines in a patient with systematized morphea.

We have previously shown that frontoparietal scleroderma en coup de sabre, a type of linear scleroderma that affects the face and scalp, follows the lines of Blaschko, but the question whether linear scleroderma that occurs in the limbs follows Blaschko's lines has not been answered. We describe the case of a 4-year-old girl with multiple morphea showing remarkable unilateral systematized distribution and whose linear lesions in the limbs appeared to follow Blaschko's lines. We suggest that linear scleroderma of the limbs, as well as frontoparietal scleroderma, may occur along the lines of Blaschko. Since both the unilateral distribution and the lesions along Blaschko's lines are the patterns created by genetic mosaicism, we suggest that a significant part of linear scleroderma and perhaps a smaller part of multiple morphea could be related to cutaneous mosaicism.