Lichen planus pigmentosus-inversus: A peculiar variant of lichen planus

Abstract

Lichen planus pigmentosus-inversus (LPP-inversus) which is an uncommon variant of lichen planus, is characterized by well bordered hyperpigmented macules and patches involving intertriginous areas. Since it was first defined, very few cases have been reported worldwide. Herein we report eight new patients with characteristic features of LPP-inversus. The hyperpigmented lesions of our patients were mostly located on axilla and the inguinal region. Two patients also had lesions that were clinically consistent with classic lichen planus. Three patients had lesions with unilateral distribution. In all of the cases a skin biopsy was performed to confirm the clinical diagnosis of LPP-inversus. LPP-inversus is a disease with unique clinical and histopathological features that we should bear in mind in the differential diagnosis of hyperpigmented flexural lesions. The etiopathogenesis and the treatment strategy of this rare entity need to be clarified.