Oral lichen planus (OLP) is a chronic inflammatory oral mucosal disease that occurs more frequently in middle-aged and elderly female patients. Previous studies indicate that OLP is a T-cell dysfunction-induced localized autoimmune disease. Clinically, six types of OLP, namely reticular, papular, plaque-like, atrophic/erosive, ulcerative, and bullous types, can be identified. OLP more commonly affects buccal mucosa, tongue, and gingiva. It always has a bilateral and symmetric distribution of the oral lesions. Plaque-like and atrophic/erosive OLP may be misdiagnosed as oral leukoplakia and oral erythroleukoplakia, respectively. Our previous study found serum autoantibodies in 195 (60.9%) of the 320 OLP patients. Specific serum anti-nuclear, anti-smooth muscle, anti-mitochondrial, gastric parietal cell, thyroglobulin, and thyroid microsomal autoantibodies are present in 28.1%, 8.4%, 1.6%, 26.3%, 21.3%, and 24.4% of 320 OLP patients, respectively. Furthermore, we also discovered that 21.9%, 13.6%, 7.1%, 0.3%, and 14.8% of 352 OLP patients have hemoglobin, iron, vitamin B12, and folic acid deficiencies, and abnormally high serum homocysteine level, respectively. Therefore, it is very important to examine the serum autoantibody, hematinic and homocysteine levels in OLP patients before starting the treatments for OLP patients. Because OLP is an immunologically-mediated disease, corticosteroids are the drugs of choice for treatment of OLP.
