Allergists market skin tests and allergy shots.

Drug companies market antihistamines, nasal sprays and skin treatments.

Other medical specialties tend to ignore or deny allergy as a cause of diseases they treat. The original concept of allergy included all immune-mediated disease and the term allergy was interchangeable with the term "hypersensitivity." A clinical immunology text will take the approach that allergy and autoimmune disease are the two major categories of hypersensitivity disease. While inflammation is increasingly recognized as a mechanism of most common diseases, the source of inflammation is seldom considered; medical attention is focused on treating the end stage disease with a number of anti-inflammatory strategies.

Allergy can be thought of as hypersensitivity disorders with external causes. Substances which trigger allergic responses are antigens, often proteins, that can be found in air, food and water. Airborne antigens such as plant pollens, fungal spores and house dust are well known. 

Other airborne antigens and food antigens are less obvious. New and foreign substances introduced to the body such as airborne chemicals, drugs and herbs cause allergic reactions as the body identifies foreign antigens and then attempts to get rid of the alien.

Food Allergy the Source of Common Diseases

Many books in the popular literature talk about food allergy, sensitivity and intolerance. The medical profession often the existence of food allergy and many MDs use the term "Food Intolerance" without understanding what they mean.

Bidndslev-Jensen C. et al suggested that: "No data demonstrate any major difference between food allergy and food intolerance concerning the type of symptoms elicited by food challenge... the time-course and dose relationship seem identical.“ The eruption of symptoms of food allergy may represent the loss of tolerance, rather than new or different sensitivities. The gastrointestinal tract in normal circumstances learns to tolerate antigens that are presented regularly. Oral tolerance to food is learned by infants as solid foods are introduced. In the best case, tolerance to regularly eaten food endures throughout the life of the individual.  Strima and Bahna reported on conceptual differences on food allergy among US physicians. 722 physicians from different specialties were polled. ENT physicians estimated the prevalence of food allergy at 21%; the mean estimate of prevalence was 12.9%. Symptom patterns were recognized in gastrointestinal tract, skin, CNS, respiratory tract and genitourinary tract. Proteins were identified as allergens by 68%, chemicals 22%, carbohydrates 7%, and fat 2%. The skin tests were not thought to be reliable and 49% of the food reactions were seen as delayed responses. Clinical manifestations of food allergy can be separated into categories according to the patterns of illness and the time-course of symptom production.

The best books and articles proclaim the benefits of diet revision and a ground-swell of interest and concern has engaged an ever-enlarging group of patients in the search for nutritional solutions to their health problems.

Often, the patients who benefit from proper diet revision are distanced from a medical profession who is not interested or denies the problem of food allergy. Some of the issues that arise are semantic and political; some of the issues arise from vested interests attempting to control public opinion. Other issues involve the complex biology of food-body interactions. Yet other issues involve the changes in the food supply which have accelerated in the past few decades.

When you do not know about food allergy mysterious diseases surround you. When you know about food allergy, a lot of common illness patterns begin to make sense. Linda Gamlin writing about food allergy in the New Scientist stated that: "Evidence is growing that many debilitating and chronic symptoms of ill health come from an intolerance for certain foods. The medical establishment finds many aspects of food intolerance difficult to swallow, but the main problem is the plethora of symptoms and the variations from one patient to another. Doctors working with food intolerance report more than 40 possible symptoms and conditions...the severity also varies. Some patients are said to have nothing more than the occasional migraine or bout of fatigue, while at the other end of the scale the sufferer is unable to work or lead any sort of normal life."