obviously without the ability to see these "blisters" first-hand i cannot offer you a patient-specific answer but many people who see blister-like growths on the pharynx (throat) are really seeing ectopic lymph tissue often referred to as "cobblestones" in the medical world. this area is rich in lymph tissue. cobblestoning can be found in a variety of medical conditions - basically anything that causes inflammation. allergies (even if no allergies were identified) and recurrent viral infections irriation from post-nasal drainage etc. all can cause these cobblestone-like effects. unless a bacterial infections is diagnosed by a culture or rapid strep test antibiotics (especially "massive" antibitoics) tend to have no curative effects. blisters filled with pus would not be common for cobblestones. if she also gets bronchitis at the same time it may not be related to this throat finding at all. most cases of bronchitis are viral. although a specific reason has not be determined by her medical providers it would be wise to keep looking.
my daughter gets blisters in her throat every few weeks some are full of pus turning into bronchitis. what causes? . she has been to ents and mds both just treating with massive antibiotics. her blood was allergy tested and none found. could it be food allergies? she had severe mono 8 years ago and her immune system seems to be compromised more than most. otherwise a healthy active 25 year old.