Lichen planus explained: symptoms and treatment

What lichen planus is

Lichen planus is an inflammatory condition thought to arise when the body's immune system mistakenly attacks cells in the skin or the linings of the mouth and other areas, causing inflammation. The exact reason this happens is not fully understood, but it is not an infection and cannot be passed from person to person. It can affect several parts of the body, sometimes more than one at a time: the skin, the inside of the mouth, the genital skin, the nails and the scalp. In many people it appears without any clear trigger, though occasionally it seems linked to certain medicines or other factors. Lichen planus is not a cancer, and for most people it is a nuisance rather than a serious threat to health, though some forms, particularly in the mouth or genital area, need longer-term attention.

The symptoms it causes

The symptoms depend on where lichen planus appears. On the skin, it typically causes small, shiny, firm bumps that are often purplish or reddish, usually on the wrists, forearms, ankles or lower back, and they can be very itchy. Sometimes fine white lines can be seen on the surface of the bumps. In the mouth, lichen planus often produces a lacy white pattern on the inner cheeks, gums or tongue, which may cause no trouble or may lead to soreness, especially with spicy or acidic foods, and sometimes ulcers. It can also affect the genital skin, causing soreness or discomfort, the nails, causing ridging or thinning, and the scalp, where it can lead to patches of hair loss. As the skin bumps settle they may leave darker or discoloured marks that fade slowly over time.

How it is diagnosed

Lichen planus is often recognised by its appearance, as the pattern of itchy purplish bumps on the skin or the lacy white markings in the mouth is quite characteristic. A doctor will usually ask about the symptoms, look at the affected areas, and check other sites such as the mouth, nails, scalp and genital skin, since more than one area can be involved. In many cases the diagnosis can be made from examination alone. Where there is doubt, or to confirm the diagnosis, a small sample of skin (a biopsy) may be taken and examined, which shows the typical features of the condition. Sometimes other tests are done, for example if a medicine is suspected of contributing or to check for associated conditions. Reaching a clear diagnosis helps guide treatment and reassures that it is not an infection or cancer.

How it is treated

There is no single cure that makes lichen planus disappear at once, and skin lichen planus often clears by itself over months to a couple of years, so treatment mainly aims to relieve itching and soreness, calm the inflammation and speed healing. For the skin, creams or ointments that reduce inflammation are commonly used, along with measures to ease itching. For the mouth, gentle oral care, avoiding things that irritate such as spicy or acidic foods, and specific treatments applied to the lining can help sore areas. Genital, nail and scalp lichen planus may need particular treatments and specialist input. In more severe or widespread cases, stronger treatments taken by mouth or other approaches may be considered under a skin specialist. Because some forms can persist or recur, ongoing review is sometimes needed to keep symptoms under control.

Living with lichen planus

Living with lichen planus is easier with a few practical habits. Keeping the skin moisturised and avoiding scratching helps reduce itching and prevents further irritation, and loose, comfortable clothing can ease discomfort. If the mouth is affected, good but gentle oral hygiene, regular dental care, and avoiding foods and drinks that sting, such as spicy, acidic or very hot items, can make a real difference, as can stopping smoking. Using treatments as prescribed and attending follow-up appointments helps keep the condition controlled. Because long-standing lichen planus in the mouth or genital area occasionally needs monitoring, it is worth reporting any new lumps, non-healing ulcers or changes so they can be checked. Reassurance that the condition is not contagious and not usually serious, combined with steady management, allows most people to cope well with the ups and downs it can bring.