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Allergy Center |
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| Alpha Health Education: Topics from the Book of Allergy and Immunology Food Allergy in Children
Immunology Center Environmed Research Inc |
There are different types of allergy. The immediate or type 1 hypersensitivity is easily recognized because it involves quick and dramatic symptoms. Hay fever is the most common expression of allergy and is a prototype of immediate hypersensitivity. Hay fever is a reaction to airborne plant pollens in the nose. Allergy tests are positive, antihistamines help and allergy shots can reduce the reactivity over time. Delayed patterns of allergy are not so obvious and generally go unrecognized. Allergy skin tests do not show this problem nor do IgE antibody tests. Common specific problems obviously related to allergy include hay fever, asthma, rhinitis, otitis media, atopic dermatitis, urticaria, and anaphylaxis Shrinking Definition of Allergy The reason for the definition of "allergy" to shrink toward a narrowly-defined clinical practice probably was the skin test. If anything distinguished an allergist from his/her colleagues, it was the skin test. By a practical evolution of allergy practice, those clinical problems which were diagnosable by skin reactions became the special property of allergists. Allergy therapy became synonymous with desensitization (immunotherapy) injections. However, the original definition of the terms "allergy" and "atopy" applied to a larger, ever expanding list of immune-mediated "strange diseases" which plague us at the end of this century of extravagant biological misadventures. For some time, it has been appreciated that food allergy operates in a more complex and mysterious way than inhaled allergy. Although skin tests were used to test for food sensitivity, many allergists also prescribed various kinds of low allergy or elimination diets on clinical grounds with satisfactory results. Allergists generally appreciated that allergy shots containing food antigens were not helpful. Nevertheless, the IgE model was the easiest route to follow in the study of food allergy. Many of the major unsolved disease of our civilization are either degenerative and/or inflammatory and many are recognized to be immune-mediated or hypersensitivity diseases. Asthma, allergy, rheumatic diseases, autoimmune diseases, multiple sclerosis, diabetes, thyroiditis, psoriasis are examples of hypersensitivity diseases which involve humoral and cell-mediated immunity. We use celiac disease - wheat allergy- as a prototype of food allergy which demonstrates the prolific ability of food allergy to produce a wide range of serious diseases. An important concern is the possibility that the chemical soup created by our civilization drives increasing numbers of individuals into hypersensitivity illness. The theory is that substances in the air, water and food supply can drive immune networks into hypersensitive states and produce a variety of diseases. Commonly quoted "expert" opinions tend to minimize the incidence and importance of food allergy. While the dogma is misleading, it represents vested interests and is remarkably persistent. The type 1 model of allergy is attractive to physicians and researchers, because of its relative simplicity and the ease of testing for sensitization; but, it selects only a special population of people with IgE-mediated allergy. While this is an important reaction pattern, some physicians have claimed it is the only valid form of allergic reactions to food. Their opinion is no longer acceptable. A distinction between immediate, obvious allergic reactions and delayed, less obvious, chronic immune injury is useful.
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