Lichen Planus Pigmentosus along the Blaschko's Lines / 대한피부과학회지

ABSTRACT

Lichen Planus Pigmentosus (LPP), an uncommon variant of lichen planus, is clinically characterized by insidious onset of diffuse or reticulated hyperpigmented patches on the sun-exposed areas and flexural folds. Histopathologic findings of LPP show atrophic epidermis with vacuolar degeneration of the basal cell layer and sparse lichenoid lymphohistiocytic infiltration with melanophages in the dermis. Although there have been few reports of LPP, clinical and histological pathogenesis and prognosis are not well known. Herein, we describe a case of linear LPP along the Blaschko's lines in 34-year old Korean man who presented with linear hyperpigmented, dark brown patches on his left thigh, repeatedly developing new lesions of erythematous reticular patches since puberty. This report shows the early events of LPP and the protracted course.