Lichen planus is characterized by a papulous itching rash of characteristic appearance of the papules and locality. The cause of the disease remains unknown. It appears between 30 to 60 years of age but generally all ages may be inflicted, although the disease is rare to the very young and old individuals. There is no gender variation. Lichen planus is characterized by shiny, planar, polygonal papules of a few millimeters which may appear deep in the center.
The deformities are usually symmetrically distributed. They are located on the wrists, forearms, sides of the neck, thighs, lower part of the back, mucous membranes of the mouth and genitals. Itching is one of the most common manifestations of the disease. In acute cases damages may expand very quickly but two to four weeks or more than four months are more frequently required after the appearance of the first deformity.
The course and duration of lichen planus depends on the extent and the location of the disease infliction. It may last from months to a few years. In 1/3 of these patients the disease may retract automatically within 8 to 12 months.
