Nancy, Have you tried seeing an immunologist? They can look for things that allergists can't. It might be worth a try. Have you had your IgE, IgG, IgA, etc. levels checked? If you see one, try to see a private practice immuno with a very good rep. IVIG might actually help you more than Pred, given everything else!
I'm glad you know what to look for. It think it is more sensible to evaluate much sooner, like you said. I hope it goes well.
Annie