Lichen planus pigmentosus inversus* * Work performed at the dermatology clinic at Guilherme Álvaro Hospital - Santos (SP), Brazil.

Líquen plano pigmentoso invertido

Hugo Rocha Barros José Roberto Paes de Almeida Sandra Lopes Mattos e Dinato Angelo Sementilli Ney Romiti About the authors

Twenty-five year old male patient presenting with asymptomatic brown spots, on cervical, axillary, inguinal and popliteal regions, for the last nine months. Pathological examination showed hydropic degeneration of the basal layer, pigmentary incontinence and moderate inflammatory lymphocytic infiltrate in the dermis. Lichen planus pigmentosus inversus is a rare subtype of lichen planus characterized by hyperchromic, asymptomatic or mildly pruritic macules, measuring from millimeters to centimeters in diameter, with defined borders, affecting intertriginous areas, most commonly in the axillae and groin of Caucasian patients. It presents unique lichenoid histology. We report a case with typical clinical features, histology and evolution.

Axilla; Groin; Lichen planus; Lichenoid eruptions; Skinfold thickness

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