Lichen planus is a condition that forms an itchy rash on the skin or in the mouth.
The exact cause of lichen planus is unknown. It may be related to an allergic or immune reaction.
Risks for the condition include:
Lichen planus mostly affects middle-aged adults. It is less common in children.
The health care provider may make the diagnosis based on the appearance of the skin or mouth lesions.
A skin lesion biopsy or biopsy of a mouth lesion can confirm the diagnosis. Blood tests may be done to rule out hepatitis.
The goal of treatment is to reduce symptoms and speed healing. If symptoms are mild, you may not need treatment.
Treatments may include:
Lichen planus is usually not harmful. It usually gets better with treatment. The condition often clears up within 18 months but may come and go for years.
If lichen planus is caused by a medicine you are taking, the rash should go away once you stop the medicine.
Call your health care provider if:
In: James WD, Berger TG, Elston DM, eds. Andrews' Diseases of the Skin: Clinical Dermatology. 11th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 12
Mirowski GW, Mark LA. Oral disease and oral-cutaneous manifestations of gastrointestinal and liver disease. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 9th ed. Philadelphia, Pa: Saunders Elseiver;2010:chap 22.