Lichen planus is an inflammatory condition in which the immune system attacks the skin, mouth, nails, or scalp, producing flat-topped, purple, itchy bumps on the skin, lacy white patches in the mouth, or ridged and thinning nails. It affects about 1% of adults and is not contagious. Lichen planus can also be triggered by medications, including some cancer immunotherapies, and a related condition, lichen planopilaris, causes scarring hair loss.

What causes lichen planus?

It is T-cell mediated, meaning immune cells target the skin. Triggers include certain medications (blood pressure drugs, antimalarials, NSAIDs, and immune checkpoint inhibitors), hepatitis C infection, and dental materials for oral disease. Often no trigger is found.

What does lichen planus look like?

Shiny, flat, purple-to-pink bumps, often on the wrists, ankles, and lower back, sometimes with fine white lines on the surface. Oral lichen planus appears as white, lace-like streaks or painful erosions inside the cheeks. Nail involvement causes ridging, thinning, and splitting. Scalp disease causes redness around follicles and permanent hair loss if untreated.

How is lichen planus treated?

Potent topical steroids or calcineurin inhibitors for limited skin and mouth disease; oral steroids, phototherapy, or systemic medications such as methotrexate, acitretin, or JAK inhibitors for widespread, nail, or scalp disease. Suspected drug triggers are reviewed and, where safe, changed. Scalp lichen planus needs early, aggressive treatment to prevent permanent loss.

How Tono treats lichen planus

Tono's board-certified dermatologists see patients with lichen planus within days, not months, by video visit in 33 states and in person at Tono clinical centers. We manage lichen planus across skin, mouth, nails, and scalp, and our supportive oncodermatology team treats immunotherapy-induced lichen planus in coordination with your oncologist so your cancer therapy can continue. Your visit ends with a written plan, prescriptions sent to your pharmacy, and follow-up scheduled with the same dermatologist. Most insurance is accepted and no referral is required.

When should I see a dermatologist for lichen planus?

See a dermatologist if you have itchy purple bumps that have lasted more than a few weeks, painful white patches in the mouth, nail changes, or scalp redness with hair loss. Oral disease needs monitoring over time.