An allergy is conventionally thought of as an excessive reaction between an antigen (allergen) and an antibody. Some people, through their genetic inheritance, produce large numbers of the kind of antibodies which cause the release of large quantities of histamine when they bind to certain antigens (allergens); histamine causes large quantities of fluid to leak out of blood vessels and tissues, resulting in the distressing symptoms of allergy - local swelling, redness, and itching. Into this category of allergic reaction come Hay Fever and Allergic Rhinitis. coeliac disease, certain forms of Asthma and Conjunctivitis, Eczema, and Urticaria. In a few people the histamine reaction occurs throughout the body (anaphylaxis) and can cause death from Shock or suffocation.
At the other extreme allergies are known to cause headaches and feelings of fullness in the head (see Headache), excessive drowsiness after eating, insomnia (see Sleep Problems), ringing in the ears (see Tinnitus), recurrent Sinusitis and ear infections (see Labyrinthitis, Middle Ear Infection), Sore Throat, Nausea and Vomiting, Diarrhoea, Constipation, flatulence, Abdominal Pain, chronic fatigue, aching joints and muscles, binge eating (bulimia), Anxiety attacks, Depression, tearfulness, unusually aggressive behaviour, apathy, Confusion, attention deficit hyperactivity disorder, inability to concentrate... In such cases mechanisms other than the classic antigen-antibody response are almost certainly involved.
Among the many substances known to cause allergic reactions are dust, house dust mites, fur and feathers, tree and grass pollens, various plants, wool and other fabrics, nickel and other metals, gases and vapours given off by gas appliances, household cleaners, paints, solvents, and plastics, pesticide residues, non-stick coatings, various drugs, including penicillin, and of course many foods and food additives.
Desensitization treatment - carefully controlled exposure to progressively stronger doses of the allergen concerned - only works if one or two substances are involved, and should only be tried if other measures fail. In the author's experience, all forms of desensitization carry a risk. In some people desensitization 'works' for a while, then the allergy returns more violently than before and is more difficult to treat. Suppressing allergy symptoms with antihistamines, steroids, and decongestants is not recommended, unless symptoms are making life unbearable; the specific homeopathic remedies given under the conditions mentioned above should be tried first.
Broadly speaking, there are two kinds of allergy, fixed allergies and cyclic allergies.
An allergy which declares itself before the age of 2. One school of thought attributes this kind of allergy to a 'leaky bowel': the walls of the bowel are such that certain proteins easily pass into the bloodstream, where they are identified as 'foreign' and trigger off antibody production. The bowel may be leaky from birth, or leakiness may develop as a result of inflammation or Candida infestation (see Candidiasis). The permanent presence in the blood of large numbers of antibodies which would not normally be there seems to encourage allergic reactions. Most fixed allergies involve single substances.
If you suspect a food, a sensible first step would be to restrict consumption and take one of the remedies listed in the Remedy Finder under Food and Drink - ten remedies are listed under 'milk makes symptoms worse', for example. If this produces good results, you could then confirm your suspicions by trying the elimination and challenge test. If the results are equivocal and allergic symptoms persist, you should seek constitutional treatment; if appropriate, your homeopath may recommend bowel cleansing and Acidophilus capsules to reduce the permeability of the bowel. If these measures do not work, desensitization may be necessary.
Tend to occur in older people, and only declare themselves after repeated exposure to certain substances - usually several substances are involved. Exposure may not always cause a reaction because, up to a point, the body develops tolerance; this is known as 'allergy masking'. In the author's experience, cyclic allergies are often a symptom of much deeper imbalances. In some people, identifying and eliminating one substance or group of substances uncovers a sensitivity to others; it is as if removing one allergy obliges the body to find another way, and sometimes a more unpleasant way, of expressing its imbalances. That is why initial treatment should be constitutional. If this fails, avoidance of specific substances is the logical next step, provided nutrition is not compromised by cutting out too many foods; if this is likely, vitamin and mineral supplements may have to be taken under supervision, and safe foods eaten in strict rotation to prevent new allergies developing. Desensitization, orthodox and homeopathic, is a last resort.
May be fixed or cyclic, and can declare themselves in many ways - as rashes, stomach upsets, mood swings, hyperactivity, aggression, general tiredness, apathy, and malaise, and as cravings. If you suspect you have a food allergy the first items to be suspicious of are: foods which upset you; foods which you crave or find difficult to resist; foods you would miss if you were asked to give them up; foods which make you feel better after having eaten them. In this context 'foods' include beverages.
Severe allergy that can be fatal. It is advised not to give peanuts to children under the age of 5 years if there is a strong family history of allergy. You need to watch biscuits, cereals, confectionery, chocolate bars, cakes, snacks, satay sauce, stuffings, Thai and Indian food.
Testing for Allergies
Orthodox and complementary medicine offer a number of tests, and there are simple tests which you can do yourself (see Self Help / Remedies section). Skin tests, also known as patch tests, are a good way of assessing sensitivity to inhaled or contact allergens but not to food substances; a single drop of allergen extract is placed on the skin and the skin is then gently scratched with a needle; if an angry wheel develops, there is an allergy. Radio absorption testing (RAST) detects antigen-antibody reactions in a blood sample by means of radioactive isotopes. Cytotoxic testing, which is expensive but accurate in 70-80 per cent of cases, involves taking a small sample of blood and examining the activity of white blood cells when exposed to suspect substances. Sublingual testing involves placing a small amount of the suspected allergen under the tongue to see if it causes a reaction; the allergen is then diluted to see at what dilution the allergic response disappears. Applied Kinesiology and Tough for Health practitioners detect allergies by placing suspect substances on the tongue and then testing the strength of various muscles, sometimes with very clear-cut results, sometimes not; weakness is taken as an indication of allergy. Dowsing with a pendulum can sometimes produce good results, and sometimes yield nothing; much depends on the dowser’s ability to keep his or her mind clear.
Self-help: There are a number of simple tests you can do yourself. If you suspect you have a food allergy, test the foods mentioned above, eliminating them one at a time. Never eliminate more than one food at a time. This is called ‘elimination and challenge’ testing. Eliminate each food for at least 4 days, then reintroduce it within 12 days. If you feel better after not eating it and worse when you reintroduce it, you are probably allergic to it. Once you have established which foods are safe, take care to eat them on a rotational basis; if you eat them too frequently, you may develop intolerance to them again.
You might try the pulse test. This involves taking your pulse before you eat a particular food and again afterwards to see if your pulse rate rises rapidly or not. If it does, you are probably allergic to that food. To take your pulse, place your fingers lightly on the thumb side of your wrist for 30 seconds, and count the number of beats. This test only works if you are calm and breathing quietly to start with, and if your pulse rate is not too variable. If your pulse rate is more or less the same on five successive occasions when you have been sitting calmly for 15 minutes or so, the test may work well for you.
If you suspect that paints, plastics, or household chemicals may be the culprit, try the ‘sniff test’. Go for an hour’s walk in the fresh air, and when you get home quickly go round the house sniffing anything which gives out a strong smell. The smell which affects you most may well be the one you are allergic to.