Acid reflux, or an allergy, or both can be causing your sore throat and mouth ulcers. You are already allergic to several food-types so you could be allergic to more foods as well. Acid reflux can be confirmed or excluded by measuring the pH value in the mouth and esophagus. You may also have an infection – bacterial, viral, or both (mixed). You can have a mouth and throat sample taken for microbiological examination (culture for bacteria and PCR for viruses).


Therapy depends upon the diagnosis. In the mean time, you can use topical antiseptics for gargling.


You may want to consult an ENT or dentist about your problem.