Lichen planus pigmentosus-inversus: case report and review of an unusual entity.

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.