An allergy is a condition in which the body reacts poorly to a substance that is harmless in similar amounts to most people. Dust, pollens, specific foods, and animal dander do not cause a problem in a normally functioning body.
When evaluating the cause of allergies, I begin with identifying food allergies or intolerances. Continuing to eat foods we are individually and genetically incapable of handling will aggravate existing allergies or make us susceptible to other allergies. Our bodies can only handle so much of an inflammatory burden before it over reacts.