Don't get anxious ,there are many lesions happens on tongue and mouth which are red n causes burning sensation sometimes patients with chronic iron deficiency or after taking broad spectrum antibiotics experiences such patches so for proper diagnosis clinical evaluation is required. Please see dentist (oral medicine) and get it checked.

Hi,please donot think anything negative,but for a confirmed diagnosis,you have to see an experienced oral and maxillofacial surgeon for your problem,so donot delay it and do the needful asap.