I went to the doctor last summer because of annoying postnasal drip. He told me I had allergies and offered me Flonase, but I declined. Then a few months later I had terrible sinus pain that was pretty much unbearable from morning until about 6 p.m. It did not bother me at night. I went on the Flonase and it helped a lot, although if I am even an hour late for my daily dose the pain can return.

Two things I forgot to tell my doctor is that all of these problems are on the left side only, and that when I sniff it stings like I got chlorinated water in my nose (this started before the Flonase). I have never had postnasal drip, stinging, or pain on the right side. Can allergies be on only one side like this? I have none of the typical allergy symptoms like itchy eyes or sneezing.

The REACTION to the allergy can be on one side. Just like you can eat something you are sensitive to and get hives in only certain places and not all over.