Lichen planus Health Article

Definition

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

Causes, incidence, and risk factors

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
  • Occasionally located on the gums
  • Poorly defined 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 occasionally form painful ulcers
• Skin lesions:
  • Usually located on the inner wrist, legs, torso, or genitals
  • Itchy
  • Symmetrical
  • Single lesion or clusters of lesions, often at sites of skin trauma
  • 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)

Signs 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.