K.W.
Wow--poor kid! I can relate, I've had allergies my entire life--my mom said I had a runny nose my entire childhood and it's not much better now--but the allergy meds do help.
Anyways, it sounds like your son has a cold to me. With his ear problems, I can see why you would worry though. I would call your Dr and see what kind of decongestant they can recommend. All the meds they have given him so far are only for infection (the drops) and his allergies, but it appears that none of them have a decongestant in them (some allergy medicines like Claritan D, do also have a decongestant though, which is why I would first check with your Dr to see.) But a decongestant will hep dry up that fluid and hopefully stop it from getting in his ears. It will also help him breathe better through his nose.
Besides that just watch his mood and his temp. If he becomes lethargic or his temp rises up above 102, I would also be concerned and take him to the Dr.
I see that this is from yesterday too--is he doing better today? My son gets a stuffy nose/cold a lot and it usually just runs it's course, but with your son's fever and his history of ear infections, I would too be concerned.
I'm sure with all of the Dr you've seen, you've done your research but I found this web page with some great info on why child get ear infections: cause, preventative treatments, etc.
http://www.ccmh.net/healthinfo/baby/earinfections.asp