Условно различают несколько типов аллергических реакций.
Первый тип, реакции немедленного типа, заключается в том, что образовавшиеся под воздействием аллергена антитела (ИгE) – фиксируются на тучных клетках. Затем при повторной встрече аллергена с ИгЕ из клеток освобождаются биологически активные вещества (медиаторы), повреждающие окружающие ткани. К реакциям такого типа относятся: анафилактический шок, крапивница, отёки Квинке, аллергический ринит и конъюнктивит, связанные с повышенной чувствительностью к пыльце и другим аллергенам, бронхиальная астма.
Второй тип реакции характеризуется тем, что здесь аллерген соединяется с тучными клетками, а затем уже ИгЕ соединяются с ними, и происходит повреждение клеток. В этих реакциях могут частично участвовать антитела классов Ж и М. При этом выделяются токсичные для клеток вещества, повреждающие их (цитотоксический тип реакции). Такой цитотоксический тип реакции наблюдается, например, при лекарственной аллергии, когда лекарственным аллергеном повреждаются клетки крови.
Третий тип реакции (иммунокомплексный) отличается тем, что аллергены (лекарственные, пищевые, вирусные и др.), попадая в организм, соединяются с антителами, чаще классов Ж и М, и образуют с ними комплексы – антиген+антитело. Этот комплекс становится фактором, повреждающим многие клетки, из клеток освобождаются медиаторы, главным образом, кинины, и развивается внутрисосудистое аллергическое воспаление с изменениями в окружающих тканях. Третий тип реакции лежит в основе таких заболеваний как системная красная волчанка, альвеолит.
К четвёртому типу реакций относятся аллергические реакции замедленного типа, т.е. те, которые развиваются через 24-48 ч после поступления в организм аллергена. В этих реакциях роль антител берут на себя непосредственно лимфоциты, на которые воздействует аллерген. Эти лимфоциты приобретают возможность соединяться с аллергеном так, что при этом в них образуются и выделяются медиаторы, так называемые лимфокины, оказывающие повреждающее действие на окружающие ткани. Вокруг места поступления аллергена скапливаются лимфоциты, макрофаги и образуются очаги с последующим некрозом и развитием соединительной ткани. Такой тип реакций лежит в основе развития некоторых инфекционно-аллергических заболеваний (инфекционная бронхиальная астма, некоторые формы энцефалитов, нейродермит и др.). Он играет также большую роль в развитии таких заболеваний как туберкулез, проказа, сифилис, а также в развитии реакции отторжения при пересадке органов.
Нужно сказать, что нередко у аллергиков могут комбинироваться сразу несколько типов аллергических реакций. Так, например, при сывороточной болезни могут развиться аллергические реакции и первого, и второго (цитотоксический), и третьего (иммунокомплексный) типов.

лечение навязчивых состояний

At this point, you may wonder whether your problem is really a skin allergy or simply an irritation. Irritation can mimic the beginning stages of an allergic reaction: dry skin, with perhaps a mild rash and itching; or, if the problem continues, swelling and cracked skin. But the difference is quite clear: irritation is liable to show up in anyone who has an intense or prolonged contact with harsh chemicals or strong detergents, or whose hands are in and out of water all day. Irritated skin loses its fatty protective cells and becomes chapped and inflamed. Housekeepers, bartenders and dishwashers get ‘dishpan hands’ (or ‘housewives’ eczema,’ as it’s sometimes died) from the sheer physical or chemical insult to their skin. And irritation is likely to develop in anyone under these conditions.

An allergic reaction, on the other hand follows a contact with a substance that is perfectly harmless for most people. And there’s usually a time lag of anywhere from a few hours to a day or two between the contact and the dermatitis. For distance, eczema from hand cream usually appears a few days after a new brand is used. , ‘

Nevertheless, irritated skin is weaker and therefore more apt to become allergic. And irritation can aggravate existing skin allergy. So while there is a difference between them, allergy and irritation go hand in hand. In fact, a large part of successful skin allergy control involves avoiding any unnecessary irritation.

*68/65/5*

Although no one knows the exact reason why one person develops sensitivity to a drug and another doesn’t, certain recognized factors may alter your vulnerability.

Nature of the Drug. Some drugs, such as milk of magnesia, rarely cause allergic reactions. Others – namely penicillin, aspirin compounds and the sulphonamides – account for 80 to 90 per cent of all allergic drug reactions. Whether or not a drug will cause allergy seems to depend on its ability (or the ability of one of its byproducts) to latch on to a protein. And once you’ve had an allergic response to one drug, you’re open to cross-reactions to chemically similar drugs. Remember, aspirin cross-reacts with other analgesics or the food colouring tartrazine. So anyone who has reacted to one drug is likely to react to new drugs.

How Old You Are. Children don’t react to drugs as often as adults do, possibly because they use less.

Other Allergies. Some evidence suggests that people with allergic diseases (hay fever, eczema, asthma and the like) tend to react more readily to drugs. Other evidence says they don’t. Nevertheless, when allergic people do react to drugs, they seem to react more seriously. For instance, an allergic person is three to ten times more likely to suffer an anaphylactic reaction to a drug than a non-allergic person.

Other Conditions. Doctors say that the risk of reacting is greater among people with a chronic illness. But, they say, that’s probably not because the people are ill but because they take a lot of drugs.

How the Drug Is Taken. Perhaps because the skin is such a sensitive organ, drugs applied topically are more prone to cause reactions than those you swallow. Because of that increased risk, certain drugs, such as penicillin and sulphonamides, are no longer used in salves. Along the same line, you may react to an oral drug if you previously reacted to the drug when it was applied to your skin. For instance, if you once reacted to mercury-containing merthiolate painted on a scratch or cut, you could eventually react to a mercury-containing diuretic.

An injected drug, however, is more likely to cause an immediate and severe reaction, since it enters the system quickly.

*57/65/5*

Some say smoke is an allergen. Others say it’s just an irritant. But there’s no doubt about one thing: people with allergies are also sensitive to tobacco smoke.

Smoking is nothing less than self-induced air pollution. And an assault on anyone within breathing distance. Cigarette smoke contains not only tar and nicotine, but also 1,500 other chemicals: benzopyrene, formaldehyde, carbon monoxide, nitrites, hydrocarbons, phenols, ammonia, aluminium, sulphur, aldehydes, hydrogen cyanide, pyridines and acrolein – just to name a few. No wonder cigarette smoke is murder on the sensitive airways of asthmatics!

Actually, cigarette smoke bothers asthmatics and non-asthmatics alike, according to a study conducted by allergist Dr Michael S. Blaiss and reported at the annual meeting of the American College of Allergists in January 1982. Whether smoking themselves or breathing the smoke of others nearby, both the seventy-two asthmatics and 322 non-asthmatics in Dr Blaiss’s study experienced a drop in ‘small airway function’ – a medical way of saying they couldn’t breathe too well.

If any of your children have asthma, you’ll be doing them an enormous favor if you don’t smoke. One study showed, for instance, that when their parents stopped smoking, nine out of ten asthmatic children improved dramatically (Annals of Allergy).

But don’t be surprised to hear your allergist tell you to stop smoking if you have any kind of allergy whatsoever. If you’re the least bit allergic, smoke of any kind will make matters worse.

‘Aside from cancer twenty years down the road, smoking is likely to be contributing to health problems you’re having right now,’ says Dr Bell.

You have more control over smokers in your own home than anywhere else. Tack up No Smoking signs if you have to. Should someone manage to sneak a light behind your back anyway, air out the place as soon as possible.

Wood smoke is related to cigarette smoke. If you have a fireplace in your house, keep the damper closed when it’s not lit. Install glass doors across the front. Have the chimney and fireplace cleaned at the end of the season to stop smoky soot from filtering into your house – and your breathing space.

(Marijuana smoke is also an allergen, and has caused hives and asthma.)

*46/65/5*

Do you notice that you feel worse:

– when the house is being cleaned?

– when the first cold snap of autumn prompts the heating to come on?

– in libraries, storerooms or other dusty areas?

– when bedding is being changed or the mattress turned?

If you answered yes to any of those questions, there’s a good chance you’re allergic to dust.

Plain ordinary house dust is one of the most common causes of allergy – especially respiratory allergy. A mere speck of the stuff may contain items as numerous and varied as algae, bacteria, cosmetics, cotton linters, feathers, hair, house dust mites, insect particles, kapok,* lead, mould, paint chips, plaster, pollen, skin scales, street dirt, wallpaper flakes and wool particles – in short, whatever happens to be floating in the air.

Probably the most allergenic ingredients of house dust are mites – minute creatures that feed on the flakes of skin we normally shed every day. House dust mites absolutely love humidity, so bedding and upholstery in damp rooms set up an ideal climate for them to thrive. Since no odourless, non-irritating, non-toxic mite-killing products exist, the best strategy against mites is to eliminate sources of moisture: repair leaks, air out damp spots and, if those methods don’t work, use dehumidifiers. And while lower humidity keeps mites in check, it also controls dust, since dust tends to cling to moisture in the air.

As you may know, regular dusting and vacuuming is a large part of dust allergy relief. Without it, rugs, curtains, toys, bookshelves and knick-knacks collect dust like magnets, providing allergic people with regular snootfuls of the stuff. So does furniture, but while overstuffed couches and chairs trap loads of dust, spare designs such as Danish modern accumulate far less. Keeping clutter to a minimum also helps.

Dust control in a child’s bedroom is especially important, considering the number of hours he or she spends sleeping and playing there. In fact, the housekeeping routine required by most allergy doctors is so rigorous it makes Army standards seem lax by comparison. The child’s room must be stripped to the barest essentials. Rugs and curtains are the first to go. Only washable, cotton curtains are allowed on the windows. Absolutely nothing can adorn the top of the dresser. Stuffed toys are out. Mattresses must be wrapped in zipped, dust-proof covers. Wardrobes are to be emptied of everything but the child’s own clothing – hung on hangers, not stacked on the shelves. Last of all, the entire room must be dusted daily and wiped from top to bottom with a mop and damp cloth twice a week.

Sounds like good advice. Only problem is, few parents have the time or energy to follow it.

‘Most mothers won’t do it, even if they say they will,’ says Constantine J. Falliers, an asthma and allergy specialist in Denver, Colorado, and editor of the Journal of Asthma. ‘Complete control is impossible.’

‘It’s impossible to do every last thing, day in and day out,’ agrees a mother of a highly allergic child. ‘I’d have to do nothing but clean. Besides, the kid goes to school and is going to run into dust sooner or later. So I do the best I can and let the rest slide. That’s all you can do, really. Dust is everywhere.’

Actually, there’s plenty you can do to control dust without becoming a full-time scrubwoman. All it takes is a few basic changes around the house. In many homes, ‘dust is everywhere’ because forced hot-air heating systems generously spread it around the house. If you have forced hot-air heat, you can check your own heating system by placing several layers of cheesecloth over the air vents for a few days. If the system is properly filtered, the cheesecloth will remain clean. But since most conventional furnace filters remove only 5 to 10 per cent of the dust, your cheesecloth may very well come up sooty -telling you that you’re breathing dust-laden air. In that case, you can place charcoal filters or washable, all-metal or cloth filters on all the hot-air ducts – or at the very least over those leading into the bedrooms and any other rooms where the dust-sensitive person spends a lot of time. Also, have the furnace and ductwork vacuumed by a professional furnace cleaning firm once a year, just before the winter heating season begins. And you can attach either a HEPA-type air filter to your heating system or plug in a portable model or two around the house. Either one allows you to let up on stringent housecleaning requirements.

*34/65/5*

Sulphur additives are a case in point. Sulphur dioxide, a main component of air pollution, is a major threat to anyone with asthma. In the form of metabisulphite and other compounds used to preserve foods, beverages and drugs, sulphur is equally liable to trigger asthma, flushing or even shock in allergic people.

Some foods are treated with sulphur as a matter of course. Unless otherwise specified, for instance, all dried fruits are automatically treated with sulphur dioxide. So is molasses. Look for fruits and molasses that are clearly labelled ‘unsulphured’.

Many wines are laced with sulphites. Unfortunately, wine and other alcoholic beverages are not required to have their ingredients listed on’ their labels.

Monosodium glutamate (MSG) is perhaps the most famous instigator of ‘restaurant allergies’. Have you ever gone out to eat Chinese food only to come home feeling headachy and nauseated? Or flushed, warm and numb throughout your arms and chest – maybe with a pain in your chest or stomach? Chances are you had a brush with ‘Chinese Restaurant Syndrome’. The root of the problem is actually MSG, a flavor enhancer used not only in Chinese but also in Japanese and South Asian cuisine, and in many packaged foods as well. In fact, MSG is sold on supermarket spice racks right next to the marjoram and mustard seed.

For years, MSG reactions were dismissed by doctors as merely imaginary, or at most a slight irritation of the oesophagus. Then reports began to appear in medical journals telling of people who developed more than just annoying numbness -some experienced asthma and serious breathing difficulties after eating anything containing MSG. Finally, two doctors in England discovered that a fellow physician had a bona fide allergy to MSG: he lost all feeling in his hands and feet – once for three years straight. He discovered, though, that if he stayed away from certain foods, especially those containing MSG, he could prevent the problem entirely. His two doctor friends ran him through a battery of food challenges and lab tests. Nerve tests showed that, for one thing, the numbness was quite real. And blood tests showed that every time he ate MSG and felt numb, his blood IgA levels rose – often regarded as a sign of allergy {Annals of Allergy, February 1982).

There are few reliable tests for food allergy; there are none for additive allergy. The only way to test for allergy to an additive is to eliminate it just as you eliminate milk or wheat. To avoid additives, though, your label reading skills have to be doubly sharp.

*22/65/5*