I used to live in Cincinnati, also high humidity. I thought I was allergic to everything but when I saw an allergist and got tested all I tested postive to was dust, clams, and cat dander (I have cats). However, I have non allergic rhinuitus, which means there are lots of things in the air that I react to. So, I'm on Singulair (also for asthma) Nasonex (at night) and Astelin, 2x a day. I still get stuffy, especially in our ski condo where there is carpeting so I also use nasal rinse 1x per day and an air cleaner.

When I lived in Cincy I was getting sinus headaches everytime a front came through. Since Cincinnati gets a lot of rain my headaches were constant. My allergy doc. here gave me Liquibid-D. It's a decongestant and I only use it when I feel the sinus pressure or headache coming on. For some reason, they often occur in the early morning.

Now that I live in a dryer climate the headaches have decreased dramatically.

And for itchey eyes I use Patanol, a prescription eyedrop.