Allergies Support Group
When the immune system responds to a foreign substance in an abnormal way, it is classified as an allergy. When the body first contacts the substance, it will not cause any reactions, but the immune system will start to produce antibodies to it and subsequent contact will trigger more dramatic responses. Depending on the allergy, the response could be mild or very severe...
Beckeroo
Have you tried sinus irrigation. I use Ocean -- it's available at drugstores. It's just saline and you use it flush the sinuses. I find it helps move stuff out -- icky but effective.
I have recently learned that most sinus infections are not bacterial infections and therefore antibiotics don't do much. The U. of Minnesota is doing research on the fungus infections that get into our sinuses and they are working to develop fugicides. Once I learned about that I quit the nose sprays and antihistimes (they mess with my mood) and just started using the Ocean. They recommend a few sprays for dryness, but it's just saline so i just use as much as I can stand. It took a few days but then things really cleared up. I have to keep at it or it all comes back.
Good luck and I hope you feel better soon. Believe me, I know how bad it can be -- I was miserable.