Hi---allergies are a problem with the immune system. It is overactive and concerned with things that will not cause the body harm. To balance the immune system, eat a plant based diet, that is, 90% of daily calories should come from plants. These provide the vitamins, minerals and tens of thousands of phyto (plant) chemicals that allow the body to function properly. Be sure to eliminate negative ingredients, which is usually most processed foods. HFCS, MSG, artificial colors, flavors and preservatives do not aid the body in any way, and who knows what the combination of them do in a vulnerable body.
If you have problems eating lots of fruits and veggies, (it is recommended we eat at least 10 servings every day, and have those be as wide a variety of possible including lots of different darkly colored foods) I have some great strategies to help. Please feel free to contact me if you'd like to know more. Good luck, D.
Edit: Eating this way also strengthens the immune system to help prevent colds and the flu, as well as cancer and other degenerative diseases.