[DoctorJac]

I would suggest that the sinuses are not the problem. It is a hypersensitive immune system. While it may seem that the immune system is working great, it appears that you are likely in a state of hyper-irritability/inflammation which brings you closer to the threshold of symptoms. So at this point, being close to that threshold, it isn't taking much to put you pretty far over the edge into full immune response to a generally non-noxious stimulus.

Many immune responses such as yours originate in the digestive tract. With your history of significant digestive problems, even though the emergent symptoms have resolved, there can be longer term consequences. Some of which are protein digestion issues. If proteins do not get broken down properly they, because of their size (large molecules) can have a damaging effect on the lumen of the intestines, making them more permeable to toxins, destroying the nutrient absorbing villi, and allowing large molecules to "leak" into the lymphatics and circulatory system as a whole. So it's possible to take nutrition and not be able to absorb it in a way the body can use, and it's possible that your food can be "mistaken" for an invading organism as it leaks through the intestinal wall.

As this happens it can trigger massive immune system responses which can bring some people into full auto-immune dysfunction, and others (such as yourself) just to the threshold of symptoms, where a little exposure to a trigger begins the nasal (and histamines in general) cascade.

It's more complex than that, but that's the general idea. While it's not a bad idea to take some of the suggestions here, as they may help with your symptoms; it's my opinion that the symptoms may be giving us a picture of what may be going on a deeper level, and should be investigated to ensure proper resolution.

One useful test would be a intestinal permeability test, and another would be a liver clearance test...just to see what's what, and then move on from there.

...my 3 cents.