Lichen planus is a condition that forms a very itchy rash on the skin or in the mouth.
Causes
The exact cause of lichen planus is unknown. It may be related to an allergic or immune reaction.
Risks for the condition include:
- Exposure to certain medicines, dyes, and other chemicals (including gold, antibiotics, arsenic, iodides, chloroquine, quinacrine, quinine, phenothiazines, and diuretics)
- Diseases such as hepatitis C
Lichen planus mostly affects middle-aged adults. It is less common in children.
Exams and Tests
Your health care provider may make the diagnosis based on the appearance of your skin or mouth lesions.
A skin lesion biopsy or biopsy of a mouth lesion can confirm the diagnosis.
Treatment
The goal of treatment is to reduce symptoms and speed healing. If your symptoms are mild, you may not need treatment.
Treatments may include:
- Antihistamines
- Medicines that calm down the immune system (in severe cases)
- Lidocaine mouthwashes to numb the area and make eating more comfortable (for mouth sores)
- Topical corticosteroids or oral corticosteroids to reduce swelling and lower immune responses
- Corticosteroid shots into a sore
- Vitamin A as a cream or taken by mouth
- Other medicines that are applied to the skin
- Dressings placed over your skin with medicines to keep you from scratching
- Ultraviolet light therapy
Outlook (Prognosis)
Lichen planus is usually not harmful. Most often, it 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.
Possible Complications
Mouth ulcers that are present for a long time may develop into oral cancer.
When to Contact a Medical Professional
Contact your provider if:
- Your skin or mouth lesions change in appearance
- The condition continues or gets worse, even with treatment
- Your dentist recommends changing your medicines or treating conditions that trigger the disorder
References
James WD, Elston DM, Treat JR, Rosenbach MA, Neuhaus IM. Lichen planus and related conditions. In: James WD, Elston DM, Treat JR, Rosenbach MA, Neuhaus IM, eds. Andrews' Diseases of the Skin: Clinical Dermatology. 13th ed. Philadelphia, PA: Elsevier; 2020:chap 12.
Patterson JW. An approach to the interpretation of skin biopsies. In: Patterson JW, ed. Weedon's Skin Pathology. 5th ed. Philadelphia, PA: Elsevier; 2021:chap 2.
Review Date 11/18/2022
Updated by: Elika Hoss, MD, Assistant Professor of Dermatology, Mayo Clinic, Scottsdale, AZ. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.