Lichen planus

Symptoms and causes

Lichen planus (LIE-kun PLAY-nus) is a condition of the skin, hair, nails, mouth and genitals. On skin, lichen planus often appears as purple, itchy, flat bumps that develop over several weeks. In the mouth and genital mucosa, lichen planus forms lacy white patches, sometimes with painful sores.

Mild lichen planus of the skin may not need treatment. If the condition causes pain or intense itching, you may need prescription medicine.

Symptoms of lichen planus vary depending on the part of the body affected. Nail disease usually affects several nails. Symptoms include:

• Purple, shiny, flat bumps, often on the inner forearms, wrists or ankles.
• Lines of rash where the skin has been scratched.
• Lacy white patches on the tongue or inside of the cheeks.
• Itchiness.
• Painful sores in the mouth or genitals.
• Rarely, hair loss.
• Nail scarring or loss.
• Dark lines from the tip of the nail to the base.

The cause of lichen planus is likely related to the immune system attacking cells of the skin or mucous membranes. It's not clear why this irregular immune response happens. The condition isn't contagious.

Lichen planus may be activated by:

• Hepatitis C infection.
• Pain relievers and other medicines.
• An allergic reaction to the metal in dental fillings.

Anyone can develop lichen planus. It most often affects middle-aged adults. Lichen planus in the mouth is more likely to affect women than men.

Lichen planus can be difficult to treat on the vulva and in the vagina. It can cause scarring and severe pain. Sores on the genitals can make sex painful.

The affected skin and nails might stay slightly darker even after healing.

Oral sores may affect your ability to eat. Oral lichen planus increases the risk of oral cancer. Rarely, lichen planus affects the ear canal. Left untreated, it may lead to hearing loss.