Hello and welcome to Healthcare Magic. Thanks for your query.

The most common possibilities for your symptom are:
- a localized infection
- an inflamation in response to an inadvertent trauma to that area while swallowing, like from a sharp piece food material
- certain vitamin deficiencies, like vitamin B2 (Riboflavin) decifiency can often produce ulcers or redness or sorenes in the mouth

I would suggest the following remedial measures:

- Gargle your mouth three to four times a day with an antiseptic mouth wash, like Chlorhexidine (should be available over-the-counter) or with Betadine gargles.

- Take frequent hot fluids, as it can help relieve the inflamation and have a soothing effect also.

- Avoid dry or sharp foods, as it can cause more irritation to the affected area.

- You can also take a multivitamin supplement, preferably one with B-complex vitamins and Vitamin C, to promote better healing

If you follow these measures, your problem should most likely subside within a few days. However, if you the blister is becoming bigger or if you are developing more lesions, then you will have to see a doctor to have a proper evaluation.

Wish you all the best.

- Dr. Jonas Sundarakumar

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