Oral lichen planus (OLP) is a chronic inflammatory disease that affects the mucosal membrane.
T-cell mediated damage against the mucosal epithelial cells is implicated in the pathogenesis
of OLP, although the exact mechanism is unknown.
Sulfasalazine is extensively used in inflammatory bowel disease and is effective on
immune-related inflammatory disease such as Crohn's disease, rheumatoid arthritis, and
Behcet's disease. In spite of its effectiveness, the anti-inflammatory mechanism is not
clearly understood.