Lichen Planus

What is Lichen Planus?

Lichen planus is a disease which presents as an itchy, swollen rash on the skin or in the mouth.

What Causes Lichen Planus?

Lichen planus is most likely related to an allergic or immune reaction, however exact cause is unknown.

Risks include:

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

Lichen planus occurs mainly in middle-aged adults, and is less common in children.


Skin lesions:

  • Can appear on the inner wrist, legs, torso, or genitals
  • Can be itchy
  • Can appear symmetrical
  • Can appear as a single lesion or a cluster, often at sites of skin trauma
  • Can present as a papule approximately 2 - 4 cm in size
  • Can have distinct, sharp borders
  • Can be covered with fine white streaks or scratch marks called Wickham's striae
  • Can be shiny or scaly in appearance
  • Can be dark in colour - reddish-purple (skin) or gray-white (mouth)
  • Can develop into blisters or ulcers

Mouth lesions:

  • Can be tender or painful (mild cases may have no discomfort)
  • Can be located on the sides of the tongue or the inside of the cheek
  • Occasionally are located on the gums
  • Can present as poorly defined areas of blue-white spots or "pimples"
  • Can present as a line of lesions that form a lacy-looking pattern
  • Can gradually increase in size
  • Occasionally form painful ulcers

Other symptoms include:

  • Dryness of the mouth
  • Loss of hair (Alopecia)
  • Metallic taste in the mouth
  • Nail ridges (nail abnormalities)


Dr. Tomi 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.


Lichen planus is generally not harmful and may improve with treatment; however, it may last for weeks to months, and may come and go for years. It usually is resolved within 18 months.


Treatment may include:

  • Antihistamines.
  • Cyclosporine.
  • Oral mouth washes containing Lidocaine, to numb the area temporarily and make eating more comfortable.
  • Oral or topical corticosteroids may reduce inflammation and suppress immune responses. Corticosteroids may be injected directly into a lesion.
  • Topical Retinoic Acid cream (a form of vitamin A) and other ointments or creams may reduce itching and inflammation.
  • Dressings may be applied over topical medications to protect the skin.
  • Ultraviolet light therapy.

Calling your Dermatologist

Call your Dermatologist if:

  • Your symptoms persist
  • The skin or mouth lesions change in appearance
  • The condition continues or worsens even with treatment

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