Lichen planus

Lichen planus (LIE-kun PLAY-nus) is an inflammatory condition that can affect your skin and mucous membranes.

On the skin, lichen planus usually appears as purplish, often itchy, flat-topped bumps. In your mouth, vagina and other areas covered by a mucous membrane, lichen planus forms lacy white patches, sometimes with painful sores.

Lichen planus occurs when your immune system mistakenly attacks cells of the skin or mucous membranes. The reason for this abnormal immune response is unknown. You can't catch lichen planus or give it to another person. Most people can manage typical, mild cases of lichen planus at home, without prescribed medical treatment. If the condition causes pain or significant itching, you may need medication to suppress your immune system.

Symptoms Causes Risk factors Complications

The symptoms of lichen planus vary depending on the areas affected. Typical signs and symptoms include:

  • Purplish, flat-topped bumps, most often on the inner forearm, wrist or ankle, but sometimes on the external genitals
  • Itching
  • Blisters that may break to form scabs or crusts
  • White spots or patches in the mouth — inside the cheeks or on the gums, lips or tongue
  • Painful oral or vaginal ulcers
  • Hair loss and scalp discoloration
  • Nail damage or loss

When to see a doctor

If tiny bumps or a rash-like condition appears on your skin for no apparent reason, such as a known allergic reaction or contact with poison ivy, see your doctor. Also, see your doctor if you experience any signs or symptoms associated with lichen planus of the mouth, genitals, scalp or nails. Because a number of skin and mucosal conditions can cause lesions and discomfort, it's best to get a prompt and accurate diagnosis.

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