Food Allergy - Delayed Hypersensitivity Immunology and Mechanisms

Flu-like symptoms are typical manifestations of the delayed patterns of food allergy - patients often complain of fatigue, irritability, aching, and cognitive dysfunction. Many say they are "sick-all over". The delayed mechanisms of food allergy tend to produce recurrent or chronic symptoms. Non IgE mechanisms are responsible for delayed patterns of food allergy that are prevalent and produce symptom complexes both generally and in target organs such as the gastrointestinal tract. These mechanisms are not demonstrable by skin tests.

Prominent allergist-immunologists such as Brennerman, Gerrard, Knicker, Hill, Brostoff and numerous others for many years made conspicuous efforts to elucidate the delayed forms of food allergy which involve the most profound immune mechanisms. Unfortunately, all the good science that has been done is now mostly ignored. Allergists for the most part act as if delayed patterns of food allergy do not exist and physicians in other specialties have no idea about food-related immune mediated disease. The only hope for patients is to resolve these problems is to take charge of their own management.

The basic idea is that delayed food allergy begins in the gastrointestinal tract mucosa and spreads inward to any body tissue if food antigens enter the circulation and interact with the circulating immune system. Incoming food antigens tend to form immune complexes, and can injury target organs by triggering inflammatory responses in a variety of ways. Knicker stated :

"Delayed adverse reactions to foods are exceedingly varied, and may involve virtually any organ system. Some reactions are classically allergic ( the same list described for immediate reactions alone), and at times may reflect delayed IgE-mediated mechanisms. Others involve a single organ system, or multiple organ systems ( e.g. the central nervous system, respiratory system, skin, musculoskeletal apparatus, gastrointestinal system, cardiovascular system etc.) with puzzling combination of symptoms."

The presence of delayed patterns of food allergy is concealed in a variety of diagnoses such as migraine headaches, asthma, eczema, irritable bowel syndrome, depression, chronic fatigue, fibromyalgia, panic disorder, and arthritis. Patients with these problems tend to have two or more manifestations concurrently in a matrix of non-specific symptoms. The grand theory of hypersensitivity disease attempts to explain these illness complexes as expressions of reactive immune networks, responding to food and airborne antigens.

The gastrointestinal tract is central to understanding all food allergy mechanisms. In addition to digestion of food and absorption of nutrients, the gastrointestinal tract acts as a secretory organ, and an immune sensing device responsible for immunization against incoming antigens and tolerance to frequently appearing antigens. The permeability of the GIT determines how much antigenic material get inside.

Businco et al reviewed food allergy in infants and children.and stated:

"Food Allergy may be defined as a complex of clinical syndromes resulting from the sensitization of the patient to one or more foods, in which symptoms manifest locally in the GI tract or in remote organs as a result of immunologic reaction. At the beginning of the century Hamburger and Schloss documented the first known cases of FA. Since then a vast array of symptoms and disorders have been attributed to the ingestion of some foods. It is virtually impossible to list the constellation of symptoms that may be due to FA."

Knowledge of the nature and mechanism of allergic reactions to foods is limited. Uncertainty about mechanisms of food reactions continues into the community where many improvised and questionable tests and treatments for food allergy or "food sensitivity" have become popular. The relative neglect of food factors in medical practice creates interesting blind-spots in the handling of patients and the understanding of disease. A major shift of popular interest in food problems, however, has created a need for better informed physicians who are ready to grapple with the real-life issues of food, eating, and the multifaceted problem of adverse reactions to food. The subject of food allergy has never assumed the importance that it is due.

An Old Problem

Consider a description of food allergy in the writings of the ancient Greek physician, Hippocrates, 2000 years ago. This description fits contemporary patients we see every day:

"But there are persons who cannot readily change their diet with impunity; and if they make any alteration in it for one day, or even a part of a day, are greatly injured thereby. Such persons, provided they take dinner when it is not their wont, immediately become heavy and inactive, both in mind and body, and are weighed down with yawning, slumbering, and thirst; and if they take supper in addition, they are seized with flatulence, tormina, and diarrhoea, and to many this has been the commencement of serious disease, when they have merely taken twice in a day the same food which they have been in the custom of taking once."

"And thus, also, if one who has been accustomed to dine, and this rule agrees with him, should not dine at the accustomed hour, he will straightway feel great loss of strength, trembling, and want of spirits; the eyes of such a person will become more pallid, his urine thick and hot, his mouth bitter; his bowels will seem, as it were, to hang loose; he will suffer from vertigo, lowness of spirit, and inactivity...If he should attempt to take at supper the same food which he was wont to partake of at dinner...these things, passing downwards, with tormina and rumbling, burn up his bowels; he experiences insomnolency or troubled and disturbed dreams; and to many of them these symptoms are the commencement of some disease."

Hippocrates described a disorder with many symptoms; dysfunction of the gastrointestinal tract is associated with disturbances of mood, energy and sleep. He noted that these symptoms may herald the onset of more serious disease. He was aware of the fascinating phenomena of addiction to the allergenic food, marked by withdrawal dysphoria if the food is not eaten regularly. This withdrawal phenomenon has been variously misconstrued, especially as "hypoglycemic reactions". The frequent occurrence of cravings for the allergenic foods and marked withdrawal discomforts make investigation and treatment of food allergy a complicated business. We can conclude from Hippocrates' clinical description that the ancient Greek patient and the contemporary-world patient have much in common.

Delayed Food Allergy Symptoms

The symptomatic process begins with the action of food materials in the digestive tract and continues into the blood stream, and then affects the function of any target organ which receives the food problem. For example:

Symptoms may be limited to the digestive tract-indigestion, abdominal pain, bloating, nausea, vomiting, and diarrhea.
Symptoms may be general or systemic - fever, fatigue, sweating, and chills.
The lungs are the target organ in food-induced bronchitis and asthma.
The joints are target organs in food allergic arthritis.
Muscles and connective tissue react with pain, stiffness, and swelling.
Weakness and reduced exertional tolerance are associated with pain.
The skin reacts with itching, rashes, hives, thickening, redness, swelling, and scaling as in eczema and psoriasis.
The brain is the target organ when disorganized, disturbed thinking, feeling, remembering, and behaving occur.

Patterns of Illness

Food allergy is a whole-body disease and a lottery selection of disturbances may evolve over many years. In many older children and adults we can trace the illness pattern back to infancy with slow, intermittent emergence of symptoms over several years. There may be intermissions of relatively good health lasting months to years. In other patients the illness begins abruptly and progresses rapidly without prior symptoms.

We can think of overlapping layers of problems which emerge over time. Food allergy may coexist with eating disorders, metabolic problems, diabetes and other disease states. Symptoms are intermittent or inconsistent, because the human body is not a linear machine but a complicated, changing, wavy device, like the weather or the sea. Illness is an expression of chaotic events.

Pain, fatigue and/or depression are common features of these illness patterns. More obvious allergy problems such as asthma, eczema, or migraine headaches may dominate the foreground, with aching, fatigue, digestive, emotional and cognitive disturbances lurking in the background; or depression may be the dominant foreground problem, while digestive and skin problems may be less important background features.

We permit uncertainty about the mechanism of the problems and focus on the likely source of the disturbance and a likely solution. I suggest that diet revision, properly conducted, will resolve a great number of problems simultaneously. Thus diet revision therapy (DRT) is an all-purpose method of resolving illness.

As the expressions of food allergy evolve over time, different parts of the body tend to get most of the activity. The nose and skin may be the first target organs and remain active for several years; then the activity may shift to the digestive tract and joints; later the lungs get attacked and years later the brain gets the brunt of the immune activation. Some patients with severe eczema seem to be spared effects on other target organs - as if their skin soaks up most the food allergy problem. Some patients have mostly brain effects for years before other target organs show the kind of activity which tells us it is food allergy; they may suffer depression, panic attacks, and/or cognitive problems.

Diagnosis

Traditional diagnostic methods try to separate each problem into individual named boxes. While this analytic, sorting procedure helps us deal with complexity, it has distinct limitations and may mislead us. An alternative method of analyzing health problems is to understand how different problems are expressions of a common, underlying disease process.

We assume that a dysfunctional matrix underlies the illness, not a single mechanism or cause. We often ask: where was the original problem? how did it get in? how was it distributed? how long did it take to act? and so on. We ask - did the problem originate in the food supply? A rational problem-solving approach might assume that the original problem might have been in the food supply and set about to change body input in a methodical manner; do the diet revision experiment. DRT tends to succeed even when other interventions fail.