What a pain in the butt this is for you. I'd be livid if I wasn't getting answers. Strep is NOTHING to play with. My sister was misdiagnosed at 5 years old, and ended up getting scarlet fever because of the misdiagnosis. Her skin peeled off of her in sheets - she looked like a zombie, S., and I'm not kidding. It also affected her joints and she couldn't walk for a few weeks.
Rheumatic fever is what can follow strep too. THAT affects the heart. We are eternally grateful that my sister didn't get that. Scarlet fever was bad enough.
Neither of my kids got high fevers with strep. One of our docs did a strep test to "placate" me, and walked into the waiting room and apologized to me in front of all the parents in there telling me that she was amazed that he had strep - his throat didn't look like it. She thanked me for asking for the strep test.
Sometimes my kids would have stomach upsets along with a little sore throat. Sometimes the strep test was negative, and then weeks later, when I'd take them back because they still weren't feeling well, the strep test would be positive. It seems like when the stomach is involved, it takes a while for strep to show as positive.
I got to the point that with EVERY sore throat, I got a strep test. Most of the time, I was right. Sometimes, especially with a high fever, it was a virus of some sort.
I do NOT know the answer to your question about allergies. I WOULD recommend that you get your child to an allergist and have a full panel of tests done. The tests are better now than they used to be.
You do have to wait a while to see positive effects of antibiotics.
I want to offer you the following advice. Type up a list of dates that you took your daughter to the doctor for this, write down the diagnosis and the treatment. Make it very easy to read. Find a ped ENT that is well thought of and take this list with you. If you have any papers from your current doc that back up your list, that's good to have. You do need to make a decision about the tonsils and adenoids. I would really want to consider this, but not until after you've had allergy testing.
You also need to discuss this issue about allergies/strep with the allergist. They know a lot of things. If he/she uncovers anything in the allergy testing, he/she can talk to the ENT and between the 3 of you, come up with a course of action to help your child.
I did a lot of this for my younger son because of his sinus infections. He also has structural abnormalities in the sinuses and a submucus cleft palate, but we didn't know at the time. Part of the work I did finding help and demanding diagnostic testing is WHY I found out about his structural problems. Thank goodness we found out. He had severe speech problems too and learning about his structure made a huge difference in our ability to get him more specialized help.
Just stand up for your child, and find other help if these doctors don't know what they are doing. You know your child. You don't have to keep running in circles with these same doctors. If you are really in St Paul, MN, I'd try the Mayo Clinic. I think you'd have some success with them.
Best of luck, S..