Question: What is (are) Oral lichen planus ?
Answer: Oral lichen planus is a inflammatory condition that affects the inside of the mouth. Signs and symptoms include patches of fine white lines and dots most commonly in the inside of the cheeks, gums, and/or tongue. Most people with lichen planus experience no to few symptoms, others may have painful sores or ulcers in the mouth. Severe lichen planus slightly increases the risk for oral cancer. Oral lichen planus may occur alone or in combination with other skin forms of lichen planus.
Source: GARD

Question: What are the treatments for Oral lichen planus ?
Answer: How might oral lichen planus be treated? It is important to identify and remove any potential agent that might have caused a lichenoid reaction. Chemicals or medications associated with development of lichen planus include gold, antibiotics, arsenic, iodides, chloroquine, quinacrine, quinidine, antimony, phenothiazines, diuretics such as chlorothiazide, and many others.[2483] Consideration regarding role of drugs that were started in recent months prior to the on set of oral lichen planus, as well as any contact allergens identified by patch testing is recommended. Symptoms may improve with the following measures: Meticulous oral hygiene Stopping smoking Topical steroids as drops, pastes, gels or sprays (e.g., triamcinolone paste) Steroid injections (intralesional triamcinolone) Mouth rinse containing the calcineurin inhibitors: cyclosporin or tacrolimus In severe cases systemic corticosteroids may be used. Other possible therapeutic agents may include: Thalidomide Systemic retinoids (acitretin or isotretinoin) Griseofulvin Azathioprine Cyclophosphamide Dapsone Metronidazole Low molecular weight heparin
Source: GARD