One thing that helps is to buy locally produced, non-pasteurized honey. It helps to "de-sensitize" them to the pollens in the local area. Another thing is to switch to an all organic foods diet. Chemicals in the environment weaken our immune system, so by avoiding foods that have been exposed to them, helps the immune system to heal. Use only "green" soaps and cleaners in the home. I am soon publishing an article with recipes for "green" cleaners, called the Frugal Green Home, watch for it. I suffered from severe allergies, so bad that I couldn't walk 10 feet without being winded. After treating it by eating only organic foods and following the "Rotation Diet*", I am now running 45 minutes a day and feel great!
*The rotation diet is a system whereby food families are rotated so that you are exposed to a certain group of foods only once a week. Even if you do not have food allergies, this diet helps the body rebuild itself.