Lichen planus is a relatively common skin disease which often goes undiagnosed. Usually found in middle aged adults (30 to 60), it is commonly located on the wrists and ankles but can occur anywhere on the body including the scalp, in the mouth or on the genitals. The lesions are often grouped and consist of flat topped, shiny, polygonal papules with a distinct violaceous color and a lacy whiteness over the surface. The eruption can be extremely itchy. When the scalp is involved, permanent scarring with hair loss can be appreciable.
When the mucous membranes of the mouth or genital areas are involved, annular or circular lesions are found, often without symptoms. White opalescence reticulated patterns are commonly found which are quite diagnostic.
Several forms of the disease can be very difficult to manage. Erosive (ulcerations) lichen planus of the mouth often requires aggressive therapy. It can be an extremely painful condition. Hypertrophic lichen planus consists of large, thickened, scaly plaques on the pretibial areas (shins) which produce severe itching and without effective therapy, can go on for twenty years or more.