"Epidemic" of the XXI century: why allergies occur

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"Epidemic" of the XXI century: why allergies occur
"Epidemic" of the XXI century: why allergies occur

The world is experiencing a significant increase in allergic diseases, especially among urban residents. Rostec experts talked about why allergies occur, what types of allergies occur most often and what science can offer for treatment at the present time.

Every tenth

Experts of the World Health Organization predict a global "epidemic" of allergies to humanity in the 21st century. Already now 10-15% of the population of Russia, according to official statistics, are allergic. In some countries, this figure reaches 30% or more. But even a century ago, allergies were not so common. For example, when in 1828 the English physician John Bostock decided to describe the symptoms of hay fever, he was able to find only 27 patients in London clinics. The term "allergy" came into use among doctors in 1916 with the filing of the Austrian pediatrician Clemens Von Pirke. The explosive increase in incidence began with generations born after 1960.

War for no reason

Allergic diseases occur due to a malfunction of the immune system. Normally, it must protect the body from infections and its own "wrong" cells, but at the same time restrain itself, not starting a "war" for no reason.

“In some people, the immune system becomes paranoid and sees danger where it really isn't. It reacts to harmless substances and the body's own tissues as infectious agents. Hypersensitivity reactions develop, "says Irina Efimova, PhD in Chemistry, Head of the Department of Allergens and Blood Products at NPO Microgen (a leading manufacturer of drugs for the treatment and diagnosis of allergies in Russia under the management of the Natsimbio holding of the Rostec State Corporation).

Hypersensitivity reactions are of different types, depending on which components of the immune system are involved in them. For example, according to the Jell and Coombs classification, allergic reactions are divided into anaphylactic (type I), cytotoxic (type II), immunocomplex (type III) and cell-mediated (type IV).

The word "allergy" is most often understood as type I reactions - anaphylactic. They arise like this. The body is in contact with antigens. In response to interaction with an antigen, immune cells produce antibodies of class E. The antibodies attach to the surface of mast cells (a type of white blood cell) found in tissues.

Mast cells are a kind of "heavy bombers", they contain "shells" - granules with mediators of allergic and inflammatory reactions, primarily histamine. After immunoglobulins E attached to the mast cells, sensitization occurred. The antigen with which the body has contacted becomes an allergen for it.

Under normal conditions, histamine is responsible for many functions in the body. His work concerns the vascular system, digestive tract, respiratory organs, and reproductive processes. However, excessive accumulation of histamine leads to the development of pathological processes. When they meet again with an allergen, mast cells begin bombardment - they release histamine and other inflammatory mediators.


The chemical formula of histamine / © ru.wikipedia.org

An inflammatory reaction develops with all its characteristic signs: swelling, redness, pain, fever, dysfunction of the affected tissues. The reaction usually occurs quickly - 5–20 minutes after contact with the allergen.

What does hay have to do with it?

Symptoms of allergic reactions are different depending on the type of allergen, the pathways of penetration into the body, the organs involved, and the individual characteristics of the person. In some people, the symptoms are subtle, for others they cause considerable suffering, and for some they are life-threatening. Different substances can become allergens. Most often, reactions develop to pollen, food and drugs, dust, pets, insect bites, mold, latex.

Of all allergic diseases, allergic rhinitis is the most common. It manifests itself in the form of a runny nose, profuse nasal discharge, itching, sneezing. Allergic rhinitis is seasonal - when symptoms occur during certain seasons, during the flowering of plants in response to their pollen. This allergy is called hay fever.

There is also the outdated term "hay fever", although in fact, hay, by and large, has nothing to do with it (like the term fever itself). People noticed that allergies occurred during the flowering of roses and haymaking, so they believed that the cause of the disease was freshly cut grass. Hence the name.

If symptoms bother all year round, they talk about year-round rhinitis. Most likely, microscopic mites are to blame for house dust, dandruff, animal hair or mold. People who come into frequent contact with occupational allergens at work (usually aerosols) can develop occupational allergic rhinitis. Allergic rhinitis is often accompanied by allergic conjunctivitis (but it can develop separately) - itching, burning, redness of the eyes, profuse lacrimation.


People noticed that allergies occur during haymaking, so they believed that the cause of the disease was freshly cut grass / © photosight.ru

Urticaria manifests itself as a nettle burn: in the form of pink blisters rising above the surface of the skin, itching. Most often it occurs in response to certain foods or medications, insect bites, pollen, helminth infestations. If symptoms persist for more than six weeks, it is chronic urticaria, and its causes are poorly understood.

Contact dermatitis may develop upon skin contact with household chemicals, cosmetics, hygiene products, latex. Blisters, rash, itching, burning sensation appear. Some people (children are much more likely than adults) develop atopic dermatitis (eczema). The skin in certain areas of the body becomes dry, red, irritated, itchy.

Food allergies are most common in young children. In response to the use of certain products, various symptoms may occur: vomiting, hives, cough, shortness of breath, swelling of the throat and respiratory failure, dizziness, weakness, pallor. In some people, allergic reactions are manifested in the form of asthma attacks - swelling and spasm of the bronchial walls. Shortness of breath occurs, breathing becomes wheezing. Often, asthma is combined with allergic rhinitis, develops against its background.


Hives / © autogear.ru

The most severe, life-threatening reaction is anaphylaxis. It can develop in response to any allergens, it depends on the individual characteristics of the organism. Redness of the skin, itchy rash, shortness of breath and discomfort in the throat occur. Breathing becomes noisy. The most severe manifestations are a drop in blood pressure and loss of consciousness (anaphylactic shock). If such a person is not immediately given medical attention, he may die.

Family matters

“The mechanisms of allergy development are well studied, which cannot be said about its causes. By and large, it is not known why some substances become allergens more often, others less often, why some people become allergic, others do not. Family history has been shown to play an important role: if your relatives have allergies, your risks are also increased. The hereditary predisposition of the body to allergic reactions is called atopy,”notes Irina Efimova.

Back in 1873, the English physician Charles Blackley noticed that hay fever and asthma were more common among educated people of high social status. He believed that allergies would become more common with the development of civilization and education, and now this prediction is coming true.

“The“hygiene hypothesis”of the growing prevalence of allergies is also popular: according to it, the modern world has become“too clean”. The body of an average city dweller is less and less likely to encounter microbes that “train” the immune system and help to properly adjust its work,”continues Irina Efimova.


Ash pollen / © Press service of NPO Microgen

Although this theory is not shared by the entire scientific community, data from some studies indicate that allergic diseases are less common among people living in rural areas. But, apparently, in reality the situation is more complicated, and the matter is not limited to "cleanliness" alone. There are other risk factors associated with the development of society.

This is a constant stay in poorly ventilated rooms with high humidity; many "dust collectors" in the home: upholstered furniture, mattresses, pillows, carpets; exposure to tobacco smoke; accommodation close to busy highways, businesses; contact with different chemicals at work; an abundance of all kinds of "chemistry" in modern dwellings.

By trial and test

Allergy diagnostics and treatment are performed by allergists-immunologists. During the first appointment, the specialist talks with the patient, asks about the symptoms, about when, how and after contact with what substances they appear, whether there are people in the family suffering from allergic reactions.

A simple, fast and reliable method for diagnosing allergies is allergy skin tests. Most often, scarification tests are carried out: several scratches are applied to the skin at a distance of 5 cm from each other and solutions of various allergens are dripped onto them. A histamine solution is applied to one of the scratches (normally it will cause an allergic reaction in any healthy person), to another one - a control solution without allergens. After 15-20 minutes, evaluate the reaction. Usually the test is carried out immediately on a panel of 15 allergens.

If a person has pronounced allergic reactions, but scarification tests showed a negative or questionable result, intradermal allergy tests are performed. Allergen solutions are injected intradermally with a needle and syringe. To diagnose contact dermatitis, an application skin test (patch test) is performed: a patch with allergens is attached to intact skin and left for 48 hours. Then the patch is removed and checked for irritation.


Skin allergy tests / © allergiyas.ru

Skin allergy tests are not dangerous, but they should not be performed if a person has had severe anaphylactic reactions, during an exacerbation of allergies and other diseases, pregnancy and lactation. If the patient is taking antihistamines or certain other medications, the test results may be skewed.

There are so-called provocative tests, in which the introduction of allergens is carried out directly into the organ, where the development of an allergic reaction is determined. For example, by inhalation. The possibility of developing systemic reactions during such testing makes this procedure dangerous, therefore it is carried out only by an allergist-immunologist in a hospital or a specially equipped office, where there is everything necessary to stop acute reactions.

Another effective method for diagnosing allergies is a blood test for specific antibodies (class E immunoglobulins), which are produced in the body for certain allergens. You can investigate the level of specific immunoglobulins E to a specific allergen or directly a panel of allergens. Such analyzes help to understand the mechanism of an allergic reaction, to determine the allergen, when it cannot be done in another way - by talking with the patient, using allergic tests.

There is an exit

First of all, allergy sufferers are advised to avoid contact with allergens. This is an effective measure, but it is often difficult to comply with. With food allergies, you can simply not eat certain foods, but, for example, protecting yourself from pollen is not so easy. We'll have to come to terms with the mass of restrictions. If you are allergic to wool and dandruff of four-legged pets, you need to give up pets, and if the house dust mite allergen is to blame, get rid of household "dust collectors" and regularly carry out wet cleaning.

The most common symptomatic treatment for allergies is by taking antihistamines on a regular basis. It is they who become salvation for many sick. These medications block histamine receptors and prevent it from causing inflammation. They are good because they quickly relieve allergy symptoms. But the main problem is not solved: there remains a malfunction in the immune system, due to which it reacts violently to harmless substances.

Some allergy sufferers are prescribed glucocorticosteroids - synthetic analogs of adrenal cortex hormones. They suppress the activity of the immune system and prevent mast cells from producing histamine. Their effects are also temporary, and they can cause numerous side effects, including suppression of the immune response, so they must be taken strictly as directed and in accordance with the doctor's recommendations.


Preparations before control for mechanical inclusions / © Press service of NPO Microgen

Currently, there is an etiotropic, that is, directed at the cause of the allergy, method of treatment. This is allergen specific immunotherapy (ASIT). Small doses of the allergen are injected into the body, gradually increasing them (by injection or sublingually) and, thus, consistently accustoming the immune system to adequately respond to this substance. The course of treatment is designed for 8-12 weeks, after which it is usually recommended to repeat the procedure the next year.

Despite the duration of therapy, this is the only way to get rid of allergies for a long time - for a period of three to five, and in some cases - up to eight years, and return to a full life without constant restrictions and medications. Currently, ASIT is used mainly for allergies to pollen and house dust.

The drugs used for therapy are mainly Russian. Today, most of the allergens produced in Russia for treatment and diagnostics are produced by the Stavropol branch of NPO Microgen (under the management of the Natsimbio holding of Rostec State Corporation). "Allergen" is the name of the branch, which produces, among other things, preparations for ASIT - water-salt extracts for injections.

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