Lichen striatus in an adult.

A 58-year-old Japanese woman with lichen striatus had asymptomatic multiple erythemato-papular plaques in arranged linear or band-like patterns over the right half side of her chest, back, and the right upper and lower extremities, following Blaschko's lines. A biopsy specimen demonstrated a dermoepidermal interface inflammation with a lichenoid lymphoid cell infiltrate into the upper and middle dermis. All lesions spontaneously cleared within 2 months. Lichen striatus in an adult should be differentiated from other acquired erythemato-papular dermatoses which may follow Blaschko's lines. Its histopathological features may mimic those of lichen planus, but it can be distinguished because of its consistent distribution on Blaschko's lines, not only in children but also in adults.