Lichen planus is a condition that affects the skin and mucous membranes, causing an itchy, inflamed rash. The inside of the mouth can be affected, too. Because symptoms tend to come and go - sometimes worsening with stress - the disorder is believed to be autoimmune in nature, although the exact cause isn't known. It can occur after exposure to some chemicals, dyes and medications including antibiotics, antipsychotics, gold (used to treat rheumatoid arthritis), diuretics and a number of other drugs. If a drug reaction is the cause, symptoms usually will go away after the medication is stopped. Lichen planus, which most often develops at middle age or later, can also be associated with Hepatitis C, so you should ask your doctor to check you for that virus with a blood test.
The main symptom is a reddish-purple itchy rash that usually occurs on the inside of the wrists and ankles but can develop elsewhere on the body -- the lower back, neck, legs, genitals, even the scalp and nails. The rash eventually goes away on its own although this can take years. The itching can range from mild to severe. Dermatologists usually treat the itch with oral antihistamines and corticosteroid creams that you apply to the affected areas; in severe cases they may prescribe systemic steroids or treat the area with ultraviolet light.
I would suggest that you consult a mind/body medicine practitioner about your persistent case. Choose one who is skilled in clinical hypnosis or imagery therapy. Hypnosis and imagery can be useful in all autoimmune disorders and all skin conditions. You also might try helpful essential fatty acids, which act as anti-inflammatory agents and also build healthy skin. You can get them by eating salmon and sardines or by adding freshly ground flax seeds to cereals and salads. I also recommend adding GLA (gamma-linolenic acid) to the diet by taking supplements of evening primrose oil or black currant oil (500 milligrams of either twice a day).
For the itching, I recommend the herb calendula (Calendula officinalis) - you can buy ready-to-use calendula skin products at health food stores. Follow the directions on the package label. You also could try chaparral (Larrea divaricata), an herb used frequently in Mexican folk medicine for inflammatory skin problems. Look for chaparral lotions or salves and follow label directions.
Andrew Weil, M.D.