Pigmented Papules and Patches of the Folds: A Case Series of Lcihen Planus Pigmentosus Inversus with Review of the Literature

We report nine cases of Lichen Planus Pigmentosus (LPP) inversus in Caucasian patients. They were 5 women and 4 men aged from 29 to 77 years with violaceous hyper pigmented ovalar or annular macules and patches mostly located at axillary folds but also groin, submammary folds, popliteal and genital regions. Histological examinations showed a band-like lymphocytic infiltrate in the upper dermis and melanophages in the papillary dermis. LPP inversus is a rare variant of LPP appearing in non-sun exposed areas. In contrast to LPP which occurs almost exclusively in dark skinned individuals, a comprehensive review of the literature revealed that about half of the cases reported of LPP inversus affects fair skinned individuals including Caucasian patients