Lichen planus is an inflammatory condition which affects the skin and mucous membranes. It is a T-cell–mediated autoimmune disease in which autocytotoxic CD8+ T cells trigger apoptosis of oral epithelial cells. On the skin, lichen planus usually appears as purplish, often itchy, flat-topped bumps. In mouth, vagina and other areas covered by a mucous membrane, lichen planus forms lacy white patches, sometimes with painful sores. There is no cure for Lichen planus. Treatment for the skin may include Antihistamines, Corticosteroides, Retinoic acid. Oral lichen planus affects approximately 1-2% of the general adult population, although the prevalence of the disease is unknown in many areas.