title: Lichen planus pigmentosus-inversus: case report and review of an unusual entity.
abstract: Lichen planus pigmentosus-inversus is a rare variant of lichen planus, with less than 20 cases reported in the medical literature. It presents as asymptomatic to mildly pruritic, hyperpigmented macules and/or patches involving intertriginous and flexural areas and skin folds in light-skinned individuals. The unique pattern of skin involvement, clinical features, and histology are distinctive. The combination of hyperpigmented lesion(s) isolated to non-sun exposed, intertriginous, and flexural areas with lichenoid histology is unique and separates it from other similar entities, such as lichen planus actinus and erythema dyschromicum perstans/ashy dermatosis. The case well highlights this unusual condition and represents the first case reported in the United States.
authors.affiliation: SaraPath Diagnostics, Sarasota, Florida, USA.
authors.forename: Erich
authors.initials: E
authors.lastname: Gaertner
authors.forename: William
authors.initials: W
authors.lastname: Elstein
mesh_terms: D006801:Humans; D017495:Hyperpigmentation / Q000175:diagnosis* / Q000473:pathology; D008010:Lichen Planus / Q000175:diagnosis* / Q000473:pathology; D008297:Male; D008875:Middle Aged