Lichen Planus Pigmentosus and Its Variants: Review and Update

Lichen planus pigmentosus (LPP) was a rare variant of lichen planus characterized by dark brown to gray pigmentation on sun-exposed areas, primarily affecting dark-skinned individuals. It involved an inflammatory response leading to pigmentary incontinence and was linked to factors like hepatitis C, sun exposure, and certain contactants. Variants included LPP-inversus, affecting flexural areas, and LPP along Blaschko's lines, associated with genetic mosaicisms. LPP could co-occur with other LP variants and autoimmune diseases. Treatment focused on avoiding triggers and using medications to reduce inflammation and pigmentation, thereby improving appearance and quality of life.