You should see your doctor to determine the cause of this lesion. You may have a simple area of irritation, or you have an oral herpes lesion (HSV-I) or a more serious condtion, such as oral cancer.
You can see your doctor for antibiotic medication. He can check to see if it is just a cold sore. Some people rub aloe gel on the affected area. Applying a cornstarch paste sometimes helps a cold sore. There are many home remedies available if it is a cold sore.
Lesions of this kind tend to go away after 4-6 days but if it persists, seek medical assistance and try not to disturb it by scratching it or touching it all the time.
