Lichen planopilaris: update on pathogenesis and treatment.

Lichen planopilaris (LPP) is considered to be a follicular variant of lichen planus. Clinical variants include classic LPP, frontal fibrosing alopecia, and the Graham-Little-Piccardi-Lassueur syndrome. The pathogenesis of LPP remains to be fully elucidated, but like other cicatricial alopecias involves the irreversible destruction of hair follicle stem cells and loss of a hair follicle's capacity to regenerate itself In the early stages of LPP, patients may have scalp pruritus, burning, tenderness, and increased hair shedding. A scalp biopsy shows a lymphocytic infiltrate involving the isthmus and infundibulum. Apoptotic cells present in the external root sheath and concentric fibrosis surrounds the hair follicle. Treatment is prescribed with the goal to alleviate patient symptoms and to halt the progression of hair loss. Treatment involves use of potent topical corticosteroids and/or intralesional corticosteroids. Options for systemic treatment include anti-inflammatory agents such as hydroxychloroquine, tetracyclines, pioglitazones, and immunosuppressive medications such as cyclosporine, mycophenolate mofetil, or systemic corticosteroids. Hair transplantation may also be an option if the disease has been in clinical remission. The management of LPP can sometimes be challenging and additional research is needed to improve outcomes for patients.