Lichen planus (LIE-kun PLAY-nus) is an inflammatory condition that can affect the skin, hair, nails and mucous membranes. On the skin, lichen planus usually appears as purplish, often itchy, flat-topped bumps, developing over several weeks. In the mouth, vagina and other areas covered by a mucous membrane, lichen planus forms lacy white patches, sometimes with painful sores.

Most people can manage typical, mild cases of lichen planus at home, without medical care. If the condition causes pain or significant itching, you may need prescription drugs.