What is lichen planus?
Lichen planus (also called lichen ruber planus) is a strongly itchy inflammation of the skin accompanied by red bumps. Lichen planus can also occur on the mucous membranes.
What is the cause?
The cause of the condition is not known. In some cases a link can be made between lichen planus and carrying viruses that cause hepatitis (inflammation of the liver).
What does it look like?
Lichen planus usually presents as small, grouped, brick-red, flat-topped papules (bumps) a few millimetres in size. On the surface of these red spots, very fine white lines are often visible, the so-called “Wickham’s striae”. The small red spots can merge into patches several centimetres across. Favourite sites are especially the wrists, feet and lower legs, but the lesions can occur over the whole skin.
There are also much rarer forms of lichen planus, such as: nail lichen planus (changes in the nail growth, in about 10% of patients); oral lichen planus (on the lining of the mouth, which can involve blisters and open areas — the erosive form); vaginal lichen planus (usually with open areas); lichen planopilaris (of the hair follicles); lichen planus of the palms and soles; drug-induced lichen planus (relatively common); hypertrophic lichen planus (with thick plaques); blistering lichen planus; actinic lichen planus (only on sun-exposed skin); and linear lichen planus (arranged in lines).
Typical of lichen planus is the so-called Koebner phenomenon: a new lichen planus lesion develops at the site of skin damage (a scratch, for example). The Koebner phenomenon is also seen in psoriasis.
Who gets it?
Anyone can develop lichen planus, but it is seen mainly in people between 25 and 70 years of age. It is almost never seen in babies and toddlers.
How is it treated?
There is no curative therapy for lichen planus, but the complaints it causes can usually be suppressed well. Possible treatments are:
- Topical corticosteroids (“hormone creams”) — usually able to suppress the itch well.
- Light therapy — UVB and PUVA courses can be given on an outpatient basis in more severe cases.
- Ciclosporin — for very severe forms; courses with this immune-influencing medicine are usually short.
- Acitretin and prednisone — can be used in severe, persistent cases.
Lichen planus of the mouth. This persistent form is difficult to treat. Corticosteroid gels, ciclosporin mouth rinses and disinfectant products are prescribed with variable success. Good oral hygiene is very important, including regular dental visits. Avoid acidic and hot foods and try to damage the mucous membrane and gums as little as possible. For a lot of pain, anaesthetic gels (lidocaine) can be prescribed.
What is the outlook?
In most cases lichen planus disappears on its own within a few years. In some people, however, it remains very persistent — the oral form in particular often persists for a very long time.
When to see a doctor
See a doctor for a persistent, very itchy rash of red bumps, or for painful sores or white patches in the mouth or genital area, so the diagnosis can be confirmed and the itch and discomfort treated.