Is there some type of exam or are there certain symptoms that facilitate a doctor's ability to make a differential dx between O.N. and severe allergies, i.e., when the eustachian tube is affected by inflammation?

Saw my doctor this week, and I sure as heck don't know which is which; the two sure feel much the same: P-a-i-n-f-u-l.

My doctor noted it - for labwork she's ordered - as ICD-9 995.3.

I do have allergies, I know that, and have been on Zyrtec for ages (pre-dating when it became an OTC); I've also had RF'ing on my C-spine related to O.N.

It's great if doctors are able to make the distinction. Is it also possible for me to know the diff. (so I know which doctor I should be seeing) when the pain is terrible? As I mentioned, the pain feels the same to me; it hits pretty much the same areas.