** Thanks for contacting with your health concern. 1. As there is a history of taking a course of antibiotics for a longer period [1 year], thus it could be oral thrush because of that, but simultaneously other causes have to excluded like: i. take an opinion of a dentist to exclude any dental anomaly [ill fitting denture] ii. consult an ENT Physician [quick visual examination and strep. test] for any other causes[infective/pathological]. iii. poor oral hygiene iv. dry mouth, addiction [smoking] v. At her age, any underlying medical condition like diabetes, iron deficiency anemia, vitamin B12 deficiency, underactive thyroid. vi. check with VDRL and HIV test to exclude sexually transmitted disease. PS. rule of thumb is that if you see a white patch anywhere in the throat suspect diphtheria and refer immediately. 2. In the meantime till you get an appointment, make sure: - maintain proper hydration - maintain proper oral hygiene [saline water gargles, and mouthwash after every meal] - stop any addiction since they propagate the formation of white spots in the mouth. PS. even after you have tried all the measures but the spot won t go away or recur, it is best to visit your doctor.