Lichen Planus

Last Updated November 2023 | This article was created by familydoctor.org editorial staff and reviewed by Peter Rippey, MD, CAQSM

What is lichen planus?

Lichen planus is a type of rash that forms on your skin, on genitalia, or in your mouth. It is marked by purple bumps that are flat and uneven in size. The bumps may have white scales or flakes on them. Often, the rash is itchy.

Lichen planus commonly occurs on your wrists, ankles, and chest. You also can get it on your scalp, nails, genitals, or the inside of your mouth. On the scalp, lichen planus may cause hair loss. Lichen planus of the nails can cause brittle or split nails. In the mouth, the rash looks like lacy white patches on the cheeks or tongue. Lichen planus of the mouth, genitals, or anus can cause soreness and a burning sensation. Sometimes lichen planus affects areas of skin where you had a cut or burn.

Men and women can get lichen planus. It can affect people of any age but is more common in middle-aged adults.

Symptoms

The prime symptom of lichen planus is itching. It can be mild or severe. The rash may consist of a few bumps or large patches. These can last for weeks or months and can return once they’ve gone away. Sometimes, the bumps leave dark brown spots on the skin. This is more common in people who are Asian, Hispanic, and Black. The brown spots are not scars and fade over time.

Lichen planus inside the mouth can cause painful sores that make it hard to eat.

What causes lichen planus?

In most cases, the cause of lichen planus is unknown. Doctors think it could be caused by an allergic reaction or immune disease. The rash breaks out when your body’s immune system attacks the skin or mucous cells. Some cases may be linked to the hepatitis C virus. Some medications also can cause it.

Lichen planus is not contagious. You cannot catch it from or give it to someone else. It is not caused by stress, but sometimes stress makes it worse.

How is lichen planus diagnosed?

Contact your doctor if you have the symptoms listed above. They can tell if you have lichen planus by looking at your rash. The doctor may do a blood test or skin biopsy. These tests help rule out other issues. For biopsy, the doctor takes skin cells from one or more of the bumps. The cells are sent to a lab to confirm the diagnosis.

Can lichen planus be prevented or avoided?

You cannot prevent lichen planus because the exact cause is unknown.

Treatment

There is no cure for lichen planus. Most of the time, the bumps caused by lichen planus go away without any treatment after about a year. However, treatment can help improve the rash and reduce symptoms.

Types of treatment include:

  • Antihistamines, such as Benadryl, to relieve itching
  • Corticosteroids to relieve itching and swelling. These come in pill, shot, gel, and cream forms.
  • Mouthwashes with lidocaine to relieve pain from mouth sores
  • Light therapy

Lichen planus of the scalp must be treated right away or the hair may not grow back.

Living with lichen planus

Treatment can help symptoms of lichen planus but does not cure it. Once the rash goes away, there is a chance it can come back. If your doctor prescribes medicine, follow the instructions. Try to avoid itching the bumps too much. There is a risk you can break the skin and cause an infection.

Questions to ask your doctor

  • Do I have lichen planus?
  • What is the likely cause of my condition?
  • What is the best treatment for me?
  • How long do I have to take medicine? What are the side effects?
  • Are there any medicines I should stop taking?
  • What can I do to relieve the pain and itching?
  • What should I do if the rash gets worse or spreads to other parts of my body?
  • Am I at risk for other health problems?
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