Tretinoin Oral Ointment has some therapeutic effects on lichen planus, as follows. 1. The main ingredient of tretinoin oral ointment is tretinoin acetate, which belongs to glucocorticoid, has the effect of anti-inflammatory, anti-allergic, analgesic, etc. It can enhance the stability of endothelial cells, smooth muscle cells, lysosomal membranes, inhibit immune response, reduce the synthesis of antibodies and histamine release, and can be used for the treatment of lichen planus. 2. Tretinoin oral ointment may appear after the use of dry mouth, burning, tingling, oral mucosal atrophy and other adverse reactions, tretinoin allergy is prohibited, should not be used for a long period of time on a large area, the use of the drug site burning sensation, redness and swelling and other symptoms should be discontinued. The above medication needs to be used under the guidance of a doctor, it is recommended to go to the hospital to receive professional treatment.