Lichen Planus: Symptoms, Causes and Treatment

Lichen planus is an inflammatory condition that can cause itchy, raised bumps and changes in mucosal skin.

Lichen planus is an inflammatory condition in which the immune system affects skin or mucosal surfaces. It may appear as purple or reddish, flat-topped bumps, often on the wrists, ankles or lower back. Some people have mouth, scalp, nail or genital involvement without obvious skin bumps.

Common skin symptoms include intense itching and groups of small, firm, flat-topped bumps. The affected areas may develop fine pale lines on their surface and can leave darker marks after inflammation settles. Mouth lesions may look like white, lacy patches or painful sores. Nail changes can include thinning, ridging or splitting.

The exact trigger is not always identified. Lichen planus reflects inflammation directed against cells in the outer skin or mucosal lining. A medicine, infection, dental material or local injury can sometimes be associated with a similar eruption, so a clinician may review your medicines and health history.

Skin flares may develop over weeks and then gradually settle, while colour changes can remain after the bumps fade. Mouth, genital, scalp and nail disease may behave differently from skin disease and can need longer follow-up. New areas can appear during an active phase.

A personal history of immune-related illness, certain infections or exposure to a medicine associated with lichenoid reactions may be relevant. These associations do not establish a cause for an individual person. Tell the clinician about prescribed medicines, supplements and recent dental work.

A dermatologist usually examines the pattern, colour and surface of the lesions and checks the mouth, nails and scalp when appropriate. A small skin sample may be recommended when the appearance is atypical or another condition needs to be excluded. Persistent mouth or genital soreness deserves direct assessment.

Treatment aims to calm inflammation, control itch and protect affected mucosal or nail areas. A clinician may prescribe a strong cream or ointment for limited skin disease, with instructions about where and how long to apply it; see [Topical Corticosteroids](/treatments/medical-dermatology/topical-corticosteroids/). More extensive or resistant disease may require tablets such as oral corticosteroids under medical supervision; see [Oral Corticosteroid Treatment](/treatments/medical-dermatology/oral-corticosteroid-therapy/).

Use fragrance-free moisturiser and gentle cleansers, keep nails short and avoid scratching. For mouth symptoms, a soft toothbrush and avoidance of personal triggers such as spicy foods may help. Ask for review if pain affects eating, sleep or sexual activity, because treatment can be adjusted to the involved site.

Untreated itch can lead to skin breaks and secondary infection. Scalp or nail inflammation may cause lasting structural change, and painful mouth or genital disease can interfere with daily life. New, persistent or changing sores should be examined rather than self-treated.

There is no reliable way to prevent every episode because the initiating trigger is often unknown. Avoiding known irritants, protecting the skin barrier and attending follow-up for mouth or genital disease can reduce aggravation and help detect ongoing inflammation early.

A dermatologist can coordinate assessment and treatment, while a dentist, oral-medicine clinician, gynaecologist or urologist may help when mucosal areas are involved. Bring a current medicine list and photos showing how a flare developed.