Lichen planus in the lines of Blaschko.

We describe three adolescents with eruptive linear lesions of the back, abdomen, and extremities distributed along the lines of Blaschko. Clinically one of these lesions resembled an epidermal nevus in its morphology and distribution. A biopsy specimen demonstrated the typical histology of lichen planus (LP). There have been fewer than 20 reported cases of childhood linear LP. Our patients demonstrate that linear LP sometimes may closely resemble an epidermal nevus and may auger the onset of more generalized LP or more involvement along the lines of Blaschko, that is, "Blaschkoian" disease. Previous studies have referred to this variant as zosteriform. Our cases are the fourth, fifth, and sixth cases of childhood LP reported to occur along the lines of Blaschko. Based on the clinical findings in our patients and a review of the English-language literature, we believe that linear LP is usually distributed along the lines of Blaschko and should be renamed lichen planus, Blaschko subtype.