Oral lichen planus.

Oral lichen planus (OLP) is a chronic, immune-mediated condition commonly affecting middle-aged women. The cause of OLP remains obscure. Strict clinical and histologic criteria need to be met to arrive at a definite diagnosis, thereby ruling out other conditions that may mimic OLP clinically and/or histologically. Although OLP is considered a premalignant condition, the risk for neoplastic change seems low.