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.
Among 20333 Swedish people aged 15 yr and above, oral lichen planus was found in 1.9%; 1.6% among men and 2.2% among women. The highest prevalences were found in the age groups 65–74 and 55–64 yr. Reticular lichen planus was the most common type, found in 77.3%. The most prevalent intraoral location of lichen planus was the buccal mucosa, which was affected in 92%.