Lichen Planus
A chronic inflammatory condition that can affect the skin, mucous membranes, nails and scalp.
Lichen planus is a chronic inflammatory condition that arises from an abnormal response of the immune system against the skin and mucous membranes. It can affect the skin, the inside of the mouth, the genital area, the nails and the scalp. The condition is not contagious and does not pass from person to person.
On the skin it appears most often as purplish, flat-topped, shiny, firm and itchy bumps. It tends to settle particularly on the inner wrists, forearms, ankles, lower back and legs. In some patients it can leave brown marks that persist for a long time after healing.
Involvement of the mouth is one of the most common forms of lichen planus. White lacy lines, redness, tenderness or painful sores can develop on the inner cheeks, tongue or gums. Lichen planus in the genital area can cause itching, burning, pain and tenderness. In patients with nail involvement, thinning, ridging, brittleness and permanent deformity of the nails can develop.
The form of lichen planus that affects the scalp is called lichen planopilaris. In this case redness, scaling, itching, burning and hair loss can be seen on the scalp. Because the condition can lead to permanent hair loss if not recognised and treated early, it is important that such scalp complaints are assessed by a dermatologist.
The exact cause of lichen planus is not fully known. Alongside genetic predisposition, mechanisms related to the immune system are thought to play a part. Factors such as some medications, infections and stress can trigger the condition to start or flare.
The diagnosis is usually made by dermatological examination. Where needed, dermoscopic examination and a skin biopsy help confirm the diagnosis.
Treatment is planned individually according to the location, extent and severity of the condition. Topical treatments, oral medications, phototherapy and, where necessary, treatments that regulate the immune system may be used. With appropriate treatment the condition can usually be brought under control; however, some patients experience flares from time to time.