Causes

The exact cause of lichen planus is unknown. However, it is likely to be related to an allergic or immune reaction.

Risks include:

• Exposure to medications, dyes, and other chemical substances (including gold, antibiotics, arsenic, iodides, chloroquine, quinacrine, quinide, phenothiazines, and diuretics)
• Disorders such as hepatitis C

Lichen planus generally affects middle-aged adults. It is less common in children.

Symptoms

• Mouth lesions
  • Tender or painful (mild cases may have no discomfort)
  • Located on the sides of the tongue or the inside of the cheek
  • Sometimes located on the gums
  • Area of blue-white spots or "pimples"
  • Lines of lesions that form a lacy-looking network
  • Gradual increase in size of the affected area
  • Lesions sometimes form painful ulcers
• Skin lesions:
  • Usually located on the inner wrist, legs, torso, or genitals
  • Itchy
  • Even on both sides (symmetrical)
  • Single lesion or clusters of lesions, often at sites of skin injury
  • Papule 2 - 4 cm in size
  • Papules clustered into a large, flat-topped lesion
  • Lesions have distinct, sharp borders
  • Possibly covered with fine white streaks or scratch marks called Wickham's striae
  • Shiny or scaly appearance
  • Dark colored -- reddish-purple (skin) or gray-white (mouth)
  • Possibility of developing blisters or ulcers

Other symptoms include:

• Dry mouth
• Hair loss
• Metallic taste in the mouth
• Ridges in the nails (nail abnormalities)

Exams and Tests

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.

Treatment

The goal of treatment is to reduce your symptoms and speed healing of the skin lesions. If symptoms are mild, you may not need treatment.

Treatments may include:

• Antihistamines
• Immune-suppressing medications, such as cyclosporine (in severe cases)
• Lidocaine mouthwashes -- to numb the area and make eating more comfortable (for mouth lesions)
• Topical corticosteroids (such as clobetasol) or oral corticosteroids (such as prednisone) -- to reduce swelling and suppress immune responses. Corticosteroids may be injected right into a lesion.
• Topical retinoic acid cream (a form of vitamin A) and other ointments or creams -- to reduce itching and swelling and aid healing
• Topical immune-suppressing medications, such as tacrolimus and pimecroliumus -- but lesions must be watched carefully for signs of cancer
• Dressings may be placed over topical medications to protect the skin from scratching.
• Ultraviolet light therapy may be helpful in some cases.
• Oral retinoids (acitretin)

Outlook (Prognosis)

Lichen planus is usually not harmful and may get better with treatment. It usually clears up within 18 months.

However it may last for weeks to months, and may come and go for years. It usually clears up within 18 months.

If lichen planus is caused by a medication, the rash should go away once the medicine is stopped.

Possible Complications

Mouth ulcers that are there for a long time may develop into oral cancer.

When to Contact a Medical Professional

Call your health care provider if:

• Your symptoms continue
• The skin or mouth lesions change in appearance
• The condition continues or worsens even with treatment
• Your dentist recommends adjusting your medications or treating conditions that trigger the disorder

References

Habif, Thomas P. Clinical Dermatology. 5th ed. Philadelphia, Pa: Mosby Elsevier;2009:pp 320-326.

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.

Updated: 4/10/2012

Reviewed by: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington School of Medicine. Also reviewed by Kevin Berman, MD, PhD, Atlanta Center for Dermatologic Disease, Atlanta, GA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.