Allergy / Hypersensitivity

This is essentially an extreme or irrational form of protective immunity where the immunological response makes a major contribution to the pathology. It is dependent on a previous stimulation of the immune system by a specific antigen or foreign agent which is called an allergen.

According to Gell and Coombs (1977) there are 4 basic classes or types of allergic response:

Type I (Anaphylaxis)
This is the most common and occurs within 2 hours of re-exposure to an allergen. Mast cells in the linings of the lungs and digestive system, and in the skin, and basophils (a type of white blood cell) carry an antibody called immunoglobulin E. produced by sensitized B lymphocytes. When the Ig. E binds with its specific antigen the mast cell or basophil ruptures and releases substances including histamine, leukotrines and kinins.

These cause: 

vasodilation leading to oedema
redness or rash
decreased blood pressure
muscular spasms especially of bronchioles
increased mucus production

The symptoms may be systemic and generalised or local. Nasal congestion, bronchial constriction (asthma), hives, urticaria, excema, arthritis, enteritis, digestive cramps, headache, loss of concentration or memory and general 'spaciness' are all common manifestations of anaphylactic allergy.

In a few people there is an extreme and almost immediate anaphylactic response to certain allergens such as bee stings or seafood. If the person is exposed then the airways will swell rapidly and the person may easily suffocate unless adrenalin is immediately administered to reduce the allergic response.

Approximately 15% of food allergies are of the anaphylactic type.

Type II (Cytolytic)
This is a result of the action of immunoglobulins G and M against antigens that are bound to other cells. When the antigen and the antibody bind 'complement factors' are activated which results in the destruction of the cell to which the antigen is bound.

The classic example of type II hypersensitivity is in the case of incompatible blood transfusions where the blood cells of the donor carry antigens that stimulate antibody reaction in the recipient. 

It is estimated that at least 75% of all food allergy reactions are accompanied by some degree of cytolytic reaction.
 

Type III (Immune Complex)
An 'immune complex' forms when an antibody (usually immunoglobulin A or M) binds with an antigen and causes agglutination and precipitation. These complexes are usually cleared out of the circulation by the white blood cells. However, if the complex is small it may become trapped under the endothelial lining of the blood vessel where it activates complement enzymes and initiates an inflammatory response.

The results of type III hypersensitivity may include glomerular-nephritis, rheumatoid arthritis and systemic lupus erythematosus (SLE).

About 80% of food allergy reactions involve some degree of type III hypersensitivity.
 

Type IV (Cell Mediated)
This is a delayed reaction mediated by T lymphocytes. Allergens entering the body are engulfed by the macrophages and presented to the T cell in the lymph nodes. T cells that are primed for that particular antigen will proliferate. 36 - 72 hours after the exposure there will be an inflammatory response. B cells and antibodies are not involved in type IV reactions.

Contact dermatitis, transplant rejection and the skin test for TB are examples of this type of hypersensitivity.

In the clinical setting food and environmental allergies are the most common type seen. In truth, anybody can be allergic to anything, and the reactions can express themselves in any area of the body or even the psyche. It is suggested that around 60% of the population suffer from some type of allergic response and this figure is slowly rising as we subject our bodies and our immune systems to ever more stress.

An allergic predisposition may be inherited if one or both parents has allergies. Three common allergic reactions are known to often be inherited: hayfever, asthma and excema. A person with one or more of this triad is said to be atopic and there is a strong family correlation although the form may switch between generations or even jump a generation. Atopic individuals have up 50% more T helper cells and hence react more rapidly to low levels of an antigen. They also tend to have low levels of digestive enzymes in the gut and to have faulty immunoglobulin A in the lining cells of the gut, both of which permit easier entry of allergens into the blood stream.

Most allergies are immune-mediated, being a reaction between antigens (allergens) and different aspects of the immune system, most commonly type I and type III hypersensitivity responses.

Any factors which impair immune function will predispose to allergy eg. stress (emotional or physical), poor nutrition, tobacco, recreational or prescription drugs, over reliance on artificial or processed foods etc.

In the case of food allergy, the condition of the digestive tract and the digestive process is very significant. Many food allergies, especially to wheat, dairy and sugar begin in early childhood when these item are introduced into the infants diet before the body is adequately equipped to handle them. Prior to one year of age the integrity of the digestive lining is poor and large molecules can cross the lining to enter the blood stream where they prime the lymphocytes against them. Ideally a baby should be weaned onto gluten-free grains (millet, buckwheat, rice), fruits and vegetables and should not receive cows milk, sugar or wheat until at least one year old.

In adults certain digestive disorders may inhibit adequate protein breakdown and may permit large protein molecules to enter the bloodstream and initiate allergic responses. Such things as deficient hydrochloric acid in the stomach, vitamin A deficiency, pancreatic insufficiency, inflammations of the stomach or intestines and abnormal gut bacteria may be factors here.

Not all adverse responses to food items involve the immune system directly. Other factors which may play a part include:

Some general symptoms of food allergy can include:

Digestive tract: Canker sores/mouth ulcers, gas and bloating, diarrhoea, gastric or duodenal ulcers, irritable bowel syndrome, malabsorption.

Urinary tract: Incontinence or bed wetting, chronic urinary tract infections.

Immune system: Chronic or repeated infections, swollen glands.

Respiratory system: Sinus congestion, ear aches or ear infections, coughing asthma, wheezing.

Skin: Rashes, acne, excema, hives, dark circles under the eyes.

Nervous system: Depression, anxiety, hyperactivity, lethargy, reduced concentration, spaciness/mental fogginess, irritably, mood swings, poor memory, insomnia, hypersomnia, migraines.

Musculo-skeletal system: Bursitis, rheumatoid arthritis.

Cardio-vascular system: Arrhythmias, fainting, oedema.

Allergies are notoriously difficult to determine because the body will frequently adapt to the situation so that the victim feels their state of health is perfectly normal.

In the initial stages of allergy development there is an acute symptomatic response following on from each exposure to that allergen and the allergy is clinically apparent. After a variable number of repeated exposures the adaptive response begins whereby the acute symptoms disappear and chronic symptoms occur. At this stage ingestion of the allergen may actually relieve symptoms temporarily and there are frequent food cravings and elements of addiction to the allergen. Part of the allergic response in the adaptive phase is an alteration in brain chemistry such that the person believes that the allergen is actually making them feel better and doesn't realise that it is just exacerbating and prolonging the problem.
 

ALLERGY TESTING
There are a number of different methods for testing for allergies, each with various advantages and disadvantages. 

R.A.S.T. Radio Allergo Sorbent Test
This is a blood test using a small amount of radio-active material to measure the presence of immunoglobulin E in the blood. It is expensive to run, raises a potential problem with the disposal of the radio-active material, and has an accuracy rate of only about 40%. 

F.I.C.A. Food Immune Complex Assay
This is a blood test that measures the amount of food molecules bound to antibodies. It is not widely available and consequently expensive, but it is slightly more accurate than the RAST system.

Cytotoxic Test
This is a blood test based on the principle that foods to which a person is reactive will produce visible damage to the WBC of the individual. Because this involves actually observing the WBC under a microscope, it is fairly subjective and not very reliable.

E.L.I.S.A. Enzyme Linked Immuno Sorbent Assay
This is a blood test which measures the amount of Ig. G as it becomes bound with enzymes in the blood, in the presence of allergens. This test is relatively accurate at measuring the occurrence of delayed hypersensitivity reactions (ie. those occurring from 2 to 24 hours after ingestion of the allergen).

Skin Prick Testing
This is a method whereby the surface of the skin is broken with either a scratch or a prick and the test allergen is introduced subdermally. Interaction of the allergen with immunoglobulin E will produce an immediately visible response of local inflammation. This method is quite uncomfortable for the patient and, while it is fairly good at determining allergy to inhalants, it is not very accurate in determining reactions to food substances.

Vega Testing
This is technically called electroacupuncture and has been used for many years in Europe. Using positive and negative electrodes it is possible to measure currents in the body (purportedly in the meridians) that change on exposure to allergens. Users of this system report it to be very accurate, cheap and painless. However, no properly objective clinical trials have yet been done to determine exact parameters for its use. 

Kinesiology
This measures the strength of certain muscles in the body which are aligned on meridians and which are affected by the presence of allergens. Although no scientifically acceptable explanations for how this system works are yet available, it is in wide use in North America and appears to hold much promise. It is, however, subjective and the accuracy of the results are very dependent on the integrity of the practitioner.

Challenge Testing (The Coca test)
This is a relatively simple procedure that you can do yourself at home. If you follow the directions carefully and take your time over it, it can be a very accurate measure of your reactivity to certain foods. It is not a suitable method for testing your reactivity to airborne allergens.

Challenge testing is best done after a period of fasting when the picture is not clouded by possible reactions to a number of different foods.

On the day before you wish to break the fast, sit quietly for 20 minutes then take your pulse at the wrist for 1 full minute. Repeat this 5 times during the day to get a clear idea of your resting pulse rate. The following day when you want to start to re-introduce solid foods, take your pulse again before eating. Now take just a small mouthful of the food you are testing, chew and swallow, then take the pulse again, for 1 minute at a time, at 1, 5, 10 and 20 minute intervals. If the pulse rate rises by more than 5 beats per minute above the resting pulse rate then this indicates an allergic response.

If no rise in the pulse rate occurs within 20 minutes then you can safely eat that food and can go on to test out the next item. In this way you can test several items in a day and can build up a clear picture of foods that are safe for you to eat.

Note that it important not to smoke or drink coffee, tea or cola while doing this pulse test as nicotine and caffeine raise the pulse rate.
 

THERAPEUTIC APPROACHES FOR TREATING ALLERGIES

Diet
Any food that you are allergic to is best avoided. If you can completely eliminate it from your diet for 6 months then the allergy may disappear. If it something which you cannot avoid then it may be necessary to go through a desensitization procedure which can be done with a naturopath or kinesiologist.

Desensitization may also be used to treat environmental allergies which you cannot avoid (eg. house dust, car exhaust fumes, formaldehyde etc). This may be done with injections or phenolics. There are also a number of practical steps you can take to minimise exposure to environmental allergens:

Nutritional supplements

Nutritional supplements may be useful to protect against the effects of allergens in your diet or environment. These include:

Vitamin C to bowel tolerance with bioflavonoids. Promotes all aspects of immune function including tissue integrity and healing.

Vitamin E (d-alpha tocopherol) 400 - 800 iu./day. Powerful anti-oxidant.

Selenium 400 mcg./day. Powerful anti-oxidant, synergist with vitamin E.

N-acetyl cysteine (NAC) 500 mg three times daily to improve liver anti-oxidant function and aid in the removal of toxins.

N-acetyl glucosamine (NAG) 500 mg three times daily. Incorporated as part of the sugar molecule that makes up mucous - causes qualitative difference in mucus production.

Evening primrose 3 g daily. Provides essential fatty acids which are anti-inflammatory and anti-allergenic.

Quercitin 1 - 2 g daily. Powerful anti-inflammatory, stabilizing to the mast cells, synergist with vitamin C. 

Royal jelly and Bee pollen as nutritional supplements. 

* L-cysteine 50 mg./day. This amino acid has a high sulphur content which is detoxifying to the body. It is a precursor to glutathione which is a powerful anti-oxidant and free radical fighter. L-cysteine is helpful in protecting against radiation and especially in protecting the liver an brain from the effects of environmental pollution. It also removes excess copper from the body and aids in the burning of fat and the building of muscle. 

* L-methionine 50 mg./day. This amino acid cannot be synthesised in the body and hence must be provided in the body. It acts, with vitamin B6, as the precursor for the formation of L-cysteine and is itself helpful in detoxification and especially in minimising allergic responses.
 
 

HERBAL REMEDIES
No herbal treatment will work against allergies, the only cure is to identify and remove the allergen. However, herbs may be useful to strengthen the immune system and also in certain symptomatic treatments.
 

EXERCISE
Aerobic exercise is a great booster of immune function - both from the improved blood flow and from the increased oxygenation of the blood. Anyone with allergies should take regular aerobic exercise (at least 20 minutes 4 times a week).

ROTATION DIETS
In people with multiple allergies there is often a tendency to develop a sensitivity to any food which is eaten too frequently and, as described above, the person often craves the very foods to which they are reacting. To minimise this problem and to stop new allergies from developing, it is helpful to follow a rotation diet where food items and food families are only consumed every 4 or 5 days. If this can be followed fro several months then frequently allergies will spontaneously resolve themselves.

Sample rotation diet (from Prescription for Natural Healing by Balch & Balch)