Что же заставляет дыхательные пути, т.е. бронхи, сжиматься, впадать в судорожное состояние или воспаляться? Ответить на этот вопрос пытаются сразу несколько теорий, но среди них есть одна, которой придерживается большинство врачей – это иммунная теория. В чём её суть?
У любого человека на любые вещества, которые попадают в организм, образуются антитела, т.е. антитела именно к этому веществу. Антитела защищают организм от воздействия этих веществ, в том числе, от очень многих микробов и вирусов. Среди антител есть одна группа – иммуноглобулин Е (ИгЕ). Когда–то, в древности, ИгЕ активно защищал первобытного человека от атак окружающей среды, но со временем, он превратился во вредное антитело. Любимое место нахождения ИгЕ в организме человека – поверхность тучных клеток.
Во внутренних стенках кожи, бронхов, носа, кишечника есть миллионы тучных клеток. Внутри каждой тучной клетки находятся сотни маленьких гранул. Внутри гранул образуются вещества, которые врачи называют медиаторами. Медиаторов много, но больше всего – гистамина. Иногда тучные клетки называют «заряженным ружьём». При вдохе в бронхи вместе с воздухом попадают различные мельчайшие вещества. У здорового человека медиаторы обычно удерживаются внутри тучной клетки, но вот у больного человека, когда из вне попадает раздражитель первый раз, сразу же запускается процесс образования ИгЕ. Эти антитела располагаются на поверхности тучных клеток и ждут своего часа. Если с воздухом вторично попадает именно опасный раздражитель, то его встречают ИгЕ на поверхности тучной клетки. Происходит «взрыв» и содержимое клетки выбрасывается на окружающие ткани. Следствием такого воздействия является резкая отёчность, жжение и воспаление.
Если тучные клетки взрываются в носу, то человек чихает, если в коже – появляется лёгкая отёчность, покраснение и зуд. А вот бронхи реагируют затруднённым дыханием, одышкой, кашлем.
Поэтому, астма более не рассматривается как заболевание, которое вызвано спазмом бронхов. Скорее, это состояние, при котором сами бронхи постоянно воспалены и сверхчувствительны. Любое вдыхаемое вещество – загрязнители воздуха, химические испарения, табачный дым и т.п. – вызывает кашель и хрипы. Правильным лечением в настоящее время считается снятие хронического воспаления при помощи таких лекарств, как кромолин и кортизон.
A similar, but much more serious case was presented by Eleanor Wyckham, an overweight middle-aged woman. Two years before entering the Ecology Unit, Mrs. Wyckham had been hospitalized for depression. She had attempted suicide twice and had been given electroshock therapy. In her case, the treatment was ineffective and caused some memory loss.
Mrs. Wyckham was one of those patients who was aware that her problems stemmed in part from food. «I’ve reached the point where I am afraid to eat any longer,» she said, before entering the Ecology Unit. «Once I start eating, I feel as if I simply cannot stop.» She alternated between binges of eating and fasts or all-fruit diets. Her favorite food in the world, she said, was peanut butter—this was the one item she could not do without. She also loved bread, baked goods, and in fact anything with wheat in it. She had eaten wheat addictively since childhood, when her mother, who was interested in nutrition, became convinced of the virtues of whole wheat bread. She therefore plied her daughter with large amounts of this staple. Mrs. Wyckham, who had a family history of alcoholism, likened herself to an alcoholic, too—in her craving for bread and peanut butter.
She entered the hospital in a very depressed state. After five days of fasting, she was much less depressed. Not surprisingly, in her food test she had a severe reaction to peanuts (as well as to lamb). More unexpected was the fact that she passed the wheat test with no trouble—which shows that food allergies cannot always be pinpointed on the basis of histories or «hunches.» She did have moderate reactions to yeast and milk, however, which are often components of bread.
Mrs. Wyckham was then retested on some of the foods to which she had had no adverse reaction, but this time to foods which had been purchased in a commercial market. There was a definite increase in her depression, after a few such meals. Through the avoidance of incriminated foods, Mrs. Wyckham was able to control both her depression and her weight problem. This points to the fact that the Rotary Diversified Diet (Chap. 18), although not specifically designed as a weight-loss diet, can be helpful in that regard for the overweight patient.
The patients described in the preceding cases appear to have become sicker gradually, after a long period of cumulative exposure to chemicals and foods. Sometimes, however, a preexisting condition is suddenly made much worse by a massive exposure to an allergy-causing substance.
*88\110\2*
How immune complexes affect the blood vessels depends very much on what sort of antibodies they contain – there are five different isotypes. In the healthy person, the main antibody formed to food is immunoglobulin A, or IgA, which has special protective properties. Unlike most other antibodies it does not activate the defensive proteins in the blood known as the complement system.
The products of the complement system cause inflammation, a reaction designed to mobilize the body’s protective forces. The effects of inflammation are to make the blood vessels in the vicinity more leaky and to attract other immune cells into the area – the leaky vessels make it easier for the immune cells to gain access to the surrounding tissues. What appears on the outside as a swollen, red, tender area is in fact a microscopic battleground, where the body’s own cells and tissues are unfortunate casualties of the general mayhem.
The purpose of inflammation, in the healthy individual, is to fight off infection. The body assumes that the antibodies have attached themselves to an invading bacterium or virus and sends in the troops. Obviously the body needs to have control systems that tell it not to react when the antibodies are bound to something innocuous – such as a food protein which happens to have wandered into the blood through the gut wall. This is the function of IgA. Because it does not activate the complement system it can quietly mop up non-harmful antigens for disposal by the phagocytes, without setting off a damaging episode of inflammation.
For this system to work, the body must somehow distinguish food from other sorts of antigen. And it must make sure that IgA – rather than IgG, another more inflammatory type of antibody – is manufactured to fit the food molecules. The details of how the body does this are still far from clear, but a general picture is emerging from current research, and this is described in Chapter Twelve. The process is known as ‘the induction of oral tolerance’.
What, if anything, goes wrong with this system? There is only a limited amount of evidence available, but it does seem that the system for producing IgA rather than IgG to food molecules breaks down in some people. Where this occurs, the immune complexes circulating in the blood after a meal will be potentially inflammatory. If they are deposited in a blood vessel, damage to the walls of the vessel will follow.
Such people may also have IgE in their food-molecule immune complexes, so mast cells could be triggered to add to the inflammation. Whether this actually happens is not clear. But if it does then there are important implications for the way we think about allergies: the dividing line between Type I (IgE) food allergy and Type III food allergy may not be as sharp as is often assumed.
*84\180\8*
Steroids are very powerful and potentially dangerous drugs which are used to prevent the inflammatory reactions that accompany allergic reactions. They are used particularly in more serious cases and are very effective.
For serious conditions, steroids may need to be taken for long periods at higher dosages, with the risk of inducing side effects which may not be readily reversible. If you have an alternative, such as avoiding the substances or foods which are triggering the disease, this is clearly better. If there is no alternative, then it is necessary to weigh up the advantages of the steroids against their risks. Ask your doctor to discuss it with you openly, so that you can make an informed decision. If you have serious disease or disability, do not refuse steroids without understanding the consequences.
Steroids should not be stopped suddenly if they have been taken for more than a few days, because they depress the natural production of steroids by the body, which must be given a chance to recover.
The worst side effects of steroids are mostly associated with prolonged oral treatments, or repeated injections, though if you use steroid creams or ointments too lavishly (particularly the stronger ones) you can absorb enough to have general effects. Side effects include facial swelling, obesity, brittle bones, high blood pressure, cataracts, diabetes, peptic ulceration, changes in mental state, and slowing the growth of children. Local effects include thinning of the skin and mucus membrane, nosebleeds, and reduced resistance to infections.
Very few people experience side effects from short courses of steroids or from the regular use of steroid inhalers, and this is the treatment of choice for moderate or severe asthma which cannot be controlled by avoiding allergens or other triggers.
Steroid inhalers (e.g. Becotide, Becloforte, Pulmicort) have less side effects than using tablets. (Sodium cromoglycate inhalers, see above, are usually tried before steroids because they can be effective, particularly with allergic asthma.) As a side effect, steroid inhalers can cause candidiasis (thrush) in the throat. This can be reduced by using a spacer, or by gargling with water after each use.
*414\117\8*
If the above is not sufficient to relieve symptoms, then you may have to take greater precautions and limit your exposure to water generally as in the detection programme above. Try any or all of those avoidance measures and see how far you need to go.
If you are exceptionally sensitive, it may be worthwhile installing a plumbed-in filtering system of some kind (see below). Some people also find it helps to use a bottled water for cooking, washing vegetables and brushing teeth, although this is costly and inconvenient. Filtered or purified water is cheaper in the long run.
Some people are very sensitive to the fumes of water when it first emerges from the tap or cistern. If this applies to you, try the following measures. Start the bath or basin filling, then leave the room while they fill, with the window open to ventilate. Return and turn off the taps. Leave the room again and leave the water to stand for a few minutes more if you need to. Avoid taking showers. The fumes are more concentrated in newly emerging water. Get someone to flush the lavatory for you, if you can. Keep the lid shut as it flushes.
*399\117\8*
If you are very chemically sensitive, you are best advised not to buy, use or travel in a brand new car. These usually give off high levels of chemical fumes and vapours from new foam, plastics and materials, particularly for the first six months. Many chemically sensitive people will be fine in a new car after six months. Some who are much more sensitive find they can only travel comfortably in a car which is at least two or three years old.
If you are thinking of buying a car, test-drive models and makes of different ages, or travel in friends’ or family’s cars, to see which age of car suits you best. If you ever have to hire a car, ask for one which is of an age that you tolerate well.
Some models and makes of car have fascia, seats and fittings made of materials which are better-tolerated by some people. The Volvo 340 range and the Volkswagen Polo, for instance, seem to be made of different materials; some people feel better in these, although others notice no difference. The Citroen 2CV and Dyane range have very little plastic fascia, and also cause fewer problems. Some people tolerate leather seats better than those of synthetic materials. Again, test-drive or try out different models or makes to see if one suits you better.
*384\117\8*
Hard lenses do not absorb fluid in the way that soft lenses do. Even in gas-permeable lenses, only a tiny amount of fluid is taken up by the lens. Preservative-based systems can therefore be used on hard lenses without trouble by the chemically sensitive, since the agent can be thoroughly rinsed off before wearing.
The rinsing solution used is a sterile saline solution sold in ozone-friendly aerosol cans. Some brands of saline are buffered with chemicals that maintain the pH of the solution; these can cause problems. Make sure you are using an unbuffered saline solution – there are half a dozen brands readily available. Ask your optician or pharmacist to check for you if you are not sure which to use.
If you use a surfactant cleaner for your hard lenses, these will be thoroughly removed by overnight soaking and rinsing in saline.
*368\117\8*
Burns and Scalds
Cool the area of the burn or scald to relieve pain. Keep the burned area in cold water or hold it under a cold running tap until the pain stops, or for at least 10 minutes. Do not prick or burst any blisters, or apply any ointment or lotion.
If the burn or scald is serious, seek emergency medical help. If the bum or scald is superficial, but rubs against clothing, cover it with a dressing of pure cotton lint and secure it with a cotton bandage. Do not use fluffy cotton wool.
Cystitis
Drinking alkali salts can ease the symptoms of cystitis. Dissolve a teaspoon of sodium bicarbonate in a glass of water and drink it. Consult your doctor if you are on a low-salt diet.
Diarrhoea
Taking arrowroot will stop diarrhoea very effectively. You can buy this as a powder at a pharmacy and make a paste by adding water. Consult your pharmacist to get the right dosage.
If you need rehydration salts after severe diarrhoea, do not take any of the proprietary ready-mixed products which can cause reactions. Rehydration salts are a mixture of sodium and potassium salts, and glucose in the right ratio; ask a pharmacist to mix these for you.
Earache
If you tolerate olive oil, warm a teaspoonful of it. Drop it into the ear, then close the earhole with pure cotton wool.
An alternative to this is sodium bicarbonate BPC, which is available in an eardrop solution.
Eyewash
For sore and itchy eyes, use a sterile saline solution to ease the itchiness. Either make a solution yourself, buy Normasol or Steripod in sachets from a pharmacist. Bathe the eyes with the solution in an eyebath, or put a few drops into the eye with a dropper.
*352\117\8*
To avoid eating soya, you have to stop eating:
Soya flour
Soya milk
Soya beans
Tofu
Soya oil TVP
Soya sauce
Miso
Soya, in its various forms, is found commonly as an ingredient in processed foods (e.g. pies, bakery, prepared dishes). Read labels to see if any of the above products are mentioned. If a product contains vegetable oil of unspecified nature, it can often be soya oil. Avoid this. If it contains vegetable protein, this is invariably soya, and should be avoided.
Lecithin is sometimes derived from soya and sometimes from eggs; products containing this (e.g. ice cream and margarine) are best avoided to be absolutely sure.
Many breads now contain soya flour as well as wheat flour. You will not know this if you buy unlabelled bread from a local baker or wholefood shop. Check with them as to what ingredients they use. Avoid bread if you are not sure whether it contains soya or not.
If you are chemically sensitive, you may react to the water used to make up processed soya milks rather than soya itself .
*116\117\8*
In intra-dermal tests, a higher dose of allergen extract is introduced just under the outer skin using a syringe. A similar weal and flare response within 10-15 minutes indicates a positive reaction. In addition, you may get a late skin reaction – a raised red swollen bump around the test site – about five or six hours later. Sometimes there may be a late skin reaction on the following day.
The infra-dermal test is much less commonly used in the UK than the skin-prick test. It can be painful, it has a slight risk of adverse reaction, and some people feel unwell on testing. It can, however, be useful in that it can detect positive reactions where skin-prick tests have previously been negative.
Patch tests are used to confirm a diagnosis of contact dermatitis – a delayed allergic skin reaction to something you have touched. Patch tests can be very useful in identifying specific things that you can then avoid. Small patches containing a range of common allergens, mostly chemicals, are attached to the skin, usually to the upper back. The sites of the tests are marked on the skin. The patches are left there for 48 hours, and then removed.
The sites are examined for reaction and then left unwashed for a further 48 hours, when the sites are examined once more. A raised red bump at the site of the allergen is an indication of positive reaction. False positives and false negatives can result, so once again patch tests are used mainly to corroborate a case history. You can use patch tests to test specific things you suspect – for instance, a fabric, a leaf or a chemical you use at work or school. You can also do a home version of the patch test for yourself.
Anti-histamine drugs block the release of histamine and can interfere with skin test results. Such drugs should not be taken for several days before testing.
*47\117\8*
If you are exceptionally sensitive to resins, wear wool, pure silk or pure synthetics if possible. You can buy resin-free cotton clothes -usually called ‘formaldehyde-free’ – for babies, children and adults. Sources are given below.
You can also find certain kinds of cotton clothes that are much less highly treated than others. These are often well tolerated even if you are sensitive to resins. If you are unable to wear wool, silk or synthetics, and want to have a wider choice of cotton clothing, choose relatively untreated cotton clothing as follows:
Try
Avoid
Take care with
Cotton jersey
Cotton poplin
Brushed cotton
Cotton fleece
Cotton drill
Cotton lawns
Cotton corduroy
Denim
Cotton voiles
Cotton towelling
Easy-care
Knitted cotton sweaters
Permanent Press
Indian cottons
Sanforised
Third World cottons
Wash New Clothes
Resins wash out readily, but not all fabrics or clothes are washed during manufacture, and new clothes can have very high levels of fumes. You can reduce the level to tolerable amounts by washing new clothes before wearing them. If you add a dessertspoonful of sodium bicarbonate to the water, this also helps to neutralise the resins. You may have to wash new clothes several times before you can wear them, but, for virtually everyone, this is sufficient to avoid any major problems. Unless you are extremely sensitive washing clothes well will make resins tolerable.
*321\117\8*
Synthetic and latex materials are conventionally described as non-allergenic and are often recommended by doctors in the belief that they do not cause allergy and that house dust mites do not thrive in synthetic materials. This advice is misleading. Synthetic and latex are useful as an alternative to wool and feathers, which commonly cause allergy, but people who are chemically sensitive often react to synthetics and latex (including plastic mattress covers as well as the bedding itself).
Synthetics and latex also harbour dust mites. To thrive, mites need warmth, moisture and human skin, bacteria or moulds as food. Bedclothes, pillows and mattresses of synthetics and latex provide these just as natural materials do. Some synthetic bedding can be washed and this helps in controlling dust mite allergy in that the mite’s faecal pellets (which are for most people the allergens) are washed out. But mites are not themselves killed by washing at the low temperatures necessary for virtually all synthetics. So they can survive the wash and continue producing faecal pellet allergens. Synthetic and latex bedding are therefore not an automatic choice for people with allergies and chemical sensitivity. They are a good choice if you are:
• allergic to wool, feathers, cotton or other natural fibres
• not chemically sensitive
Do not use a plastic or vinyl mattress cover even if you do not react to plastics. It prevents the mattress airing, keeps in damp and aggravates house dust mite problems. Use a small plastic sheet under the area that needs protection against bedwetting.
*253\117\8*
If you want to keep a dog, some breeds are reported to be less troublesome than others. Allergy is very idiosyncratic, however, and these may not work for you, so take care. Many people with allergies say that dogs that require a lot of grooming are more likely to cause reactions than dogs that do not, because more hair is shed and more contact is necessary. Dogs that have shorter, wiry hair generally shed more dander than long-haired dogs, but dogs with soft, curly hair, such as small poodles’ are sometimes found to be less provocative.
If you are blind and have to keep a guide dog, it may be best to choose a type of dog that sheds less hair, or needs less grooming, such as curly-coated retrievers, or cross labradors.
Be careful with children and animals at school. Small mammals are often kept in schoolrooms and these may be responsible for your child’s reactions. School cats are also often allowed to roam out of school hours and can leave allergens to upset the exceptionally sensitive. Watch out for the ‘school run’ if your child travels regularly in a car in which dogs travel.
*185\117\8*
Что же заставляет дыхательные пути, т.е. бронхи, сжиматься, впадать в судорожное состояние или воспаляться? Ответить на этот вопрос пытаются сразу несколько теорий, но среди них есть одна, которой придерживается большинство врачей – это иммунная теория. В чём её суть?