Does Benadryl Help In Treating Tonsil Infection?
No, Benadryl will not help.
Detailed Answer:
I'm sorry you are suffering with tonsillitis.
Did you have a throat swab done for culture and is it Strep? How long have you been on the Z-pack? And do you have a fever - how high, and is it getting any better?
Antibiotics in the penicillin family such as Amoxicillin are generally a better choice if it is Strep, but the Z-pack should do the trick too. However if you have been on the Z-pack more than 2-3 days and there is not even slight improvement at all then I'd recommend going in for reevaluation: a second look and possibly a different antibiotic. If the pain is "tremendous" as you describe, you might have developed a peritonsillar abcess, which will need to be incised to drain. Either way, if you aren't getting better and if you are in severe pain, then go in to be seen.
Benadryl is an antihistamine and will not help with the throat pain.
There are over the counter throat sprays that will numb the throat for awhile. You might want to consider trying that.
Good luck, and I hope you feel better soon.
Here are some thoughts...
Detailed Answer:
For the stuffy/runny nose that is probably causing post nasal drainage which is either exacerbating or the main cause of your throat pain, you can try a corticosteroid nasal spray such as Flonase. It's over the counter now. Takes a few days to really kick in. It is helpful regardless of whether the cause of symptoms is infection or allergies.
If there is a question of seasonal allergies causing post nasal drainage, then you could try Benadryl. Zyrtec may be a better choice as it tends to have fewer side effects and can be less drying and sedating. Takes at least an hour to kick in, lasts 12-24 hours.
If you and your doc are pretty sure the throat pain is being caused by infection, a throat swab would be a good idea. Either the Z-pack didn't work because the cause of your drainage is viral (in which case no antibiotic will work) or it is a resistant bacteria. If a culture is done, the lab can also run a "sensitivity" where they test the bacteria, that grows on the culture, against different antibiotics to see what it is sensitive or resistant to. This is a simple standard test called "culture and sensitivity" and only requires a swab to do it. The Z-pack may have decreased the bacterial count, but if there is some bacteria that is resistant to it, it will grow in the culture.