Linear atrophoderma, first described by Moulin, is an acquired unilateral dermatitis localized along the Blaschko lines. It affects children or adolescents of both genders, involving the trunk and the limbs. It is, presumably, a rare cutaneous form of mosaicism. The differential diagnosis of atrophoderma of Moulin involves congenital dermopathies along the Blaschko lines, atrophoderma of Pasini and Pierini, and linear scleroderma. We present here a peculiar case of linear atrophoderma affecting a teenager.