Lichen planus presenting as generalized reticulate pigmentation with sole involvement

Abstract

A 61-year-old Indian male presented with gradually progressive generalized reticulate brownish pigmentation of the trunk, upper limbs, and lower limbs. The face and neck area were conspicuously spared. There was no oral, scalp or nail involvement. However, the soles showed bilaterally symmetrical well-demarcated erythematous hyperkeratotic plaques. There was no history of violaceous pruritic lesions over the body. Histopathological features of the trunk as well as sole lesions were consistent with findings of lichen planus (LP). LP pigmentosus is a variant of LP seen in Indian and other darker-skinned populations and most commonly presents as diffuse pigmentation over sun-exposed areas, mainly the face and neck. Our patient, however, presented with reticulate pattern of pigmentation, sparing the face and neck, along with lesions over both the soles. Such a manifestation in the absence of typical lesions of LP is very rare and to our knowledge this is the first such case reported from the Indian subcontinent.