Lichen planus is a condition that can cause swelling and irritation in the skin, hair, nails and mucous membranes. On the skin, lichen planus usually appears as purplish, itchy, flat bumps that develop over several weeks. In the mouth, vagina, and other areas covered by a mucous membrane, lichen planus forms lacy white patches, sometimes with painful sores.
Most people can manage typical, mild cases of lichen planus at home, without medical care. If the condition causes pain or significant itching, you may need prescription drugs. Lichen planus isn’t contagious.
The signs and symptoms of lichen planus vary depending on the areas affected. Typical signs and symptoms are:
Lichen planus occurs when your immune system attacks cells of the skin or mucous membranes. It’s not clear why this abnormal immune response happens. The condition isn’t contagious.
Lichen planus can be triggered by:
Lichen planus can be difficult to manage on the vulva and in the vagina, causing severe pain and sometimes leaving scars. Sexual dysfunction can become a long-term complication. Oral sores may affect your ability to eat. The affected skin might stay slightly darker even after the rash clears up, especially in dark-skinned people.
Oral lichen planus increases the risk of oral cancer. Left untreated, lichen planus of the ear canal may lead to hearing loss.
Your doctor makes a diagnosis of lichen planus based on your symptoms, your medical history, a physical examination and, if necessary, the results of lab tests. These tests may include:
Lichen planus on the skin often clears up on its own in months to years. If the disease affects your mucous membranes, it tends to be more resistant to treatment and prone to recur. Whatever treatment you use, you’ll need to visit your doctor for follow-up appointments about once a year.
Corticosteroids: The first choice for treatment of lichen planus is usually a prescription corticosteroid cream or ointment. If that doesn’t help and your condition is severe or widespread, your doctor might suggest a corticosteroid pill or injection.
Oral anti-infection drugs: Other oral medicines used in selected situations for this condition are the antimalarial hydroxychloroquine (Plaquenil) and the antibiotic metronidazole (Flagyl, others).
Immune response medicines: Severe signs and symptoms may require prescription medications that suppress or modify your body’s immune response, such as azathioprine (Azasan, Imuran), mycophenolate (Cellcept), cyclosporine (Gengraf, Sandimmune, others) and methotrexate (Trexall).
Antihistamines: An antihistamine medication taken by mouth might relieve the itching of lichen planus.
Light therapy: Light therapy (phototherapy) may help clear up lichen planus affecting the skin. The most common phototherapy for lichen planus uses ultraviolet B (UVB) light, which penetrates only the upper layer of skin (epidermis). Light therapy usually requires two to three treatments a week for several weeks. This therapy isn’t recommended for dark-skinned people, who have an increased risk of their skin staying slightly darker even after the rash clears up.
Retinoids: If your condition doesn’t respond to corticosteroids or light therapy, your doctor might prescribe a retinoid medication taken by mouth, such as acitretin (Soriatane). Retinoids can cause birth defects, so these drugs aren’t recommended for women who are pregnant or may become pregnant. If you’re pregnant or nursing, your doctor may opt to delay topical retinoid therapy or choose a different treatment.