Encyclopedia / L / Lichen Planus

Lichen Planus


Lichen planus is a chronic, itchy skin disease of unknown cause, characterized by small, purplish bumps or patches of skin having fine, gray lines on the surface.


Common sites of involvement are the flexor surfaces of wrists, forearms, ankles, abdomen, and sacrum. Nails may have ridges running lengthwise. On mucous membranes (e.g., the mouth), the membranes appear gray and lacy.

Episodes of disease activity, of which there are numerous variations, may last for months and may recur. In more extreme cases, patients are in pain, with erosions and ulcerated areas.

There seems to be a relationship between the oral form and the skin form of lichen planus in that almost half of those with the oral version also have it on the skin.


It affects about 1 percent of the population, predominantly women, and usually appears during the fifth or sixth decade.

Possible causes of oral lichen planus include non-steroidal, anti-inflammatory drugs (NSAIDS), iodides, tetracycline, gold, streptomycin, hydrochlorothiazide, dental fillings containing mercury in the form of amalgam (if the patient is allergic to mercury), and rough fillings.

Causes may have an allergic reaction pattern, particularly following exposure to dyes and color film developers.

Links have been seen with alopecia areata, vitiligo, chronic ulcerative colitis, and graft-versus-host reactions.


Itching is mild to severe. The lesions are violet colored, flat-topped, bumps or patches discrete or in clusters, on the flexor surfaces of the wrists and on the penis, lips, tongue, and buccal (mouth) mucous membranes.

Mucosal lichen planus has been reported in the genital and anorectal areas. The papules may become bullous or ulcerated. The disease may be generalized.


Diagnosis is based on the medical history and physical examination. A skin biopsy may be recommended.


Patients with lichen planus are sometimes tense and nervous, and episodes of dermatitis may be temporarily related to emotional crises. Measures to relieve anxiety are helpful. Topical corticosteroids are often useful. Topical tretinoin cream 0.05% applied to mucosal lichen planus followed by topical corticosteroid cream may be beneficial.

In severe cases, oral corticosteroids may be prescribed. Psoralens plus long-wave ultraviolet light (PUVA) can be effective for chronic lichen planus.


Do any tests need to be done to diagnose lichen planus or to rule out other diseases?

What type of treatment will you be recommending?

Will you be prescribing any medications? What are the side effects?

If nothing is done about this problem, will it spontaneously go away? Can the lesions spread to other areas?

What measures can be taken to help relieve the discomfort?