Lichen Planus Pigmentosus Inversus: A Rare Subvariant of Lichen Planus Pigmentosus.

Lichen planus pigmentosus inversus (LPPI) is a rare subvariant of Lichen planus pigmentosus (LPP), presenting with sharply defined brown to gray macules, papules, and plaques limited to the intertriginous areas, with only a few cases reported in the medical literature so far. While LPP mostly affects patients with Fitzpatrick skin type III-IV in sun-exposed areas such as the neck, LPPI is seen in Caucasians and spares sun-exposed areas. Skin lesions tend to be very refractory to treatment attempts including potent topical steroids and oral corticosteroids. Given the increased penetration of potent topical steroids and the high risk of skin atrophy, especially when applied to intertriginous areas, this case shows that topical calcineurin inhibitors (tacrolimus 0.1%) might offer an effective and safe treatment option for LPPI.