Why does lichen planus cause skin bumps?

Lichen planus is an inflammatory skin condition. Immune activity near the junction between the outer and deeper skin layers can cause compact, flat-topped or slightly shiny bumps. They may look reddish, violaceous, or darker than nearby skin, depending on skin tone and how long they have been present.

The bumps can cluster around the wrists, ankles, lower back, or legs. Scratching may create new areas along lines of irritation and can leave temporary or longer-lasting dark marks after the inflammation settles. Similar changes can affect the mouth, nails, scalp, or genital skin, so the appearance and location matter when a clinician assesses them.

Avoid picking and reduce friction from tight clothing, rough fabrics, or repeated rubbing. Use a bland, fragrance-free moisturiser regularly, keep nails short, and try a cool compress when itching flares. A clinician may prescribe an anti-inflammatory cream or another treatment selected for the body area and the thickness of the bumps. Do not apply a strong product to the face, folds, or genital skin without tailored advice.

Arrange an assessment if bumps are persistent, spreading, intensely itchy, bleeding, painful, or changing in appearance. Seek prompt care for sores that do not heal, new mouth or genital ulcers, eye symptoms, or a widespread rash with fever. A dermatologist can distinguish lichen planus from other causes of raised bumps and check areas that may need different treatment.

Ask whether the pattern and location fit lichen planus, whether a skin sample is useful, which treatment is suitable for each affected area, and how to manage itch without damaging the skin.