Hi,
I have many different allergies but no cf (my daughter has cf), but I can think of a few things that might be helpful.
One thing I have found helpful is probiotics. Another is that if I can minimise my exposure to allergens in general, any reaction I do have is lessened. It's like one allergen exposure can trigger the immune system to be on 'hyper-alert' and consecutive reactions are worse. For example: I get terrible hayfever (grass pollen allergy), but if I cut down on the grass grains in my diet (wheat, barley, rye) my whole system calms down dramatically. I also find dairy consumption to affect my condition, with cream and icecream in particular causing wheezing. I have a theory that this might be because cows eat an entirely grass and grain based diet, but have no idea if that's what it is!
Apart from those preventative measures, I guess the usual anti-histamines could be helpful for you.
Oh and one more thought- could it be possible to take a trip to a different environment for the weeks of the year that your triggers are in season? I find being by the sea very helpful.