Erythroplakia is a flat re patch or lesion in the mouth that cannot be attributed to any other pathology. There are many other conditions that are similar in appearance and must be ruled out before a diagnosis of erythroplakia is made. Sometimes, a diagnosis is delayed for up to two weeks in order to see if the lesion spontaneously regresses on its own or if another cause can be found. Erythroplakia frequently is associated with dysplasia, and is thus a pre-cancerous lesion.