Lichen planus (LP) is a disease of the skin and mucous membranes that resembles lichen. It is thought to be the result of an autoimmune process with an unknown initial trigger. There is no cure, but many different medications and procedures have been used to control only the symptoms The overall prevalence of lichen planus in the general population is about 0.1 - 4%. It generally occurs more commonly in females, in a ratio of 3:2, and most cases are diagnosed between the ages of 30 and 60, but it can occur at any age Oral lichen planus is relatively common, It is one of the most common mucosal diseases. The prevalence in the general population is about 1.27-2.0%, and it occurs more commonly in females than males
Airborne contact dermatitis refers to acute and chronic dermatitis of exposed parts of the body, especially the face, caused by particles suspended in the air. These particles may include fibres, dust, vapours, sprays, gases, and plant materials .
Lichen planus lesions are so called because of their "lichen-like" appearance and can be classified by the site they involve and by their morphology
Lichen planus may be categorized as affecting mucosal or cutaneous surfaces
Cutaneous forms are those affecting the skin, scalp, and nails.
Mucosal forms are those affecting the lining of the gastrointestinal tract (mouth, pharynx, esophagus, stomach, anus), larynx, and other mucosal surfaces including the genitals, peritoneum, ears, nose, bladder and conjunctiva of the eyes.
Signs and symptoms:
Although lichen planus can present with a variety of lesions, the most common presentation is as a well-defined area of purple-coloured, itchy, flat-topped papules with interspersed lacy white lines (Wickham's striae).This description is known as the characteristic "6 P's" of lichen planus: planar (flat-topped),purple,polygonal, pruritic, papules, and plaques.
The cause of lichen planus is unknown, but it is not contagious and does not involve any known pathogen. It is thought to be a T cell mediated autoimmune reaction (where the body's immune system targets its own tissues This autoimmune, T cell mediated process is thought to be in response to some antigenic change in the oral mucosa, but a specific antigen has not been identified.
Drug reactions, with the most common inducers including gold salts, beta blockers, antimalarials, thiazide diuretics, furosemide, spironolactone, Metformin and penicillamine.
Reactions to amalgam (metal alloys) fillings.
Graft-versus-host disease lesions, which chronic lichenoid lesions seen on the palms, soles, face and upper trunk after several months.
Hepatitis, specifically hepatitis B and hepatitis C infection, and primary biliary cirrhosis. It has been suggested that lichen planus may respond to stress, where lesions may present during times of stress.It has also been suggested that mercury exposure may contribute to lichen p