May be a partially treated infection
I am Dr Mittal, MD.
I have read your query in detail.
There are two possibilities that I think I will discuss with you.
I think that you have probably developed some infection. Yes I know you have had antibiotics, but was a culture done prior to antibiotics? I doubt that. So what you may have is a partially treated salivary gland
infection. So everytime you eat and the gland is activated, the bacteria swell up the gland and then subsides.
It would need a prolonged antibiotic course to treat this.
Secondly, you may have some kind of food allergy
. So the swelling occurs when the food is there. Is pain there. ? The means to observe this would be to observe if the swelling occurs in one types of foods. If so, avoiding that food may help. I could suggest some tests, but eventually you will have to do the same thing- avoid the food. So you might as well observe that directly.
Was the swelling continuous at the start of the swelling? If so, then the possibility of infection is higher.
Hot saline gargles and mouth wash after each meal will help heal faster.
compress if the swelling and pain (if any) is too much.
For any further query, please feel free to put up the question. I will be glad to answer.
Dr Saumya Mittal