With the manifestation of this mysterious disease people faced long before the emergence of the term "allergy". If you believe the ancient Egyptian chroniclers, allergic shock from lightning died in 2540 BC, Pharaoh Menes after he was bitten by a wasp. In the papyrus, which dates from about 1600 BC, there is a fairly accurate description of allergic bronchial asthma.
When they opened the
And yet the first to seriously interested in allergy, was the great physician Hippocrates. In the V century BC, he described the strange skin rashes, and the most severe indigestion, appearing in some of his patients after eating certain foods. Galen, a Roman physician of Greek origin, in the II century BC, without knowing it, described allergic rhinitis. Very much surprised him that one of his contemporaries, smelling a rose, and began to sneeze strained. Roughly a millennium later took up the study of allergies Arab physician Avicenna. His discovery was "a cold spring," which appears in flowering plants. To treat this type of allergy Avicenna suggested by mummy: ingest and smear nose. Many people helped.
For a long time about the allergy no one remembered. However, this is not surprising. In those days it was not too common disease. Only at the beginning of the XIX century, it has finally started talking. And the first was an English physician John Bostock. In 1819, he performed at London Medical and Surgical Society with a sensational report on the "periodic case of the eye and chest."
Interestingly, Bostock was interested person. He himself suffered "intermittent defeat" in the scientific work described the symptoms of his illness. Not knowing her true reasons, Bostock suggested that escalating the spring and summer disease something to do with hay. And he gave it the name "hay fever."
The fact that the hay is not to blame, the first thought of a Russian doctor L. Silich. In its report on the "summer colds" at a meeting of the Society of Russian doctors in St. Petersburg in 1889, he proved that the cause of the "hay fever" — quite vibrant and, most importantly, flowering plants, especially cereals. When the pollen from the flowers up in the air, people accidentally inhale it, and as a result some of them start to sneeze, gasp and cry.
The term "allergy" appeared only in the beginning of XX century. It came up with an Austrian pediatrician Clemence perks in 1906, when he noticed that some of the children the introduction of diphtheria serum leads to unusual reactions. A scientist called this phenomenon "allergy" (from the Greek words "allos" — «other" and "ergia" — «the ability to act").
The study of
Once the name of the disease appeared, all immediately wanted to learn it. At first, it was decided to consider allergy disease in which the body responds to the unnatural, seemingly ordinary exposure. But such a definition was too broad. What is "unnatural response"? What impact is considered "normal"? For example, a pain in the finger — a common occurrence, but what if the answer instead of a simple inflammation developed gangrene? This can be considered an unnatural response or not? Aif bitten by a common wasp, a man took, and died?
How to distinguish from other allergic diseases? Why did she come from? How to fight it? To answer all these questions had to create a special area of medicine — Allergist — the science of allergies. First of all, the allergist dealt with the "normal effects" that cause allergies. It was found that the disease can cause contact only with special substances foreign to the body — "allergens."
To date, there are more than 20,000 of allergens, the most famous of which — pollen, foods, microscopic fungi spores, dust mites, animal dander and, insect venom, drugs and dyes. I allergens are several ways to get into the human body: the skin (including mucosal) through the digestive tract and the respiratory tract. But more often it happens that the allergen is effective immediately on all sides. Thus, pollen deposited on the surface of the skin, we breathe it with air, and sometimes even swallowed.
Once scientists have figured out what is considered an allergen, it was the turn elucidate the mechanism of the disease. As seemingly harmless pollen or hair can cause an allergic reaction? And found the answer to this question. Allergy culprit was officially recognized by the immune system that is available to everyone and is responsible for the persistence of the organism, protection against infections and other foreign substances. Once in the body of harmful bacteria, for any reason, deteriorated own cell infiltrated allergen,- Immune system is activated, finds and destroys enemy. The name of this set of security measures immune response.
A few words about immunity
All of us have heard about immunity. Sometimes a strong immune system, is weak. People with weak immune systems get sick more often, with a strong — often. Immunity to certain diseases can be especially elaborate. We know that if once have had "chicken pox" or "German measles", then would not get sick. On this principle has special vaccines against influenza, hepatitis and other diseases. Immunity occurs as follows. When a foreign substance (according to scientific — antigen) enters the body, the immune system is adopted for the fight with him.
The most important stage of the immune response is called sensitization (from the English word sensibility — sensitivity), ie the development of sensitivity to a particular antigen. Cells of the immune system are in contact with unfamiliar particle "detect" and its response start to synthesize specific proteins — antibody. A huge number of antibodies released into the body, and at the first opportunity they bind to an antigen on a "lock and key". Such complexes are "antigen-antibody" is a kind of target that the immune system is able to "feel" and destroy.
After all the foreign agents are neutralized, the immune system gradually returns to its original state. That's only antibodies persist for a long time. If the same antigen again fall intoorganism, it will be quickly identified, attacked ready for action antibodies. And immediately destroyed. So goes the immune response in healthy people.
However, sometimes the immune system breakdowns occur, and it starts very actively respond to quite harmless substance. For example, on the same cat hair or pollen. The body starts to self destructive immune excessive response, the results of which we used to call an allergy. The most common allergic reaction — immediate type. So there is an allergic bronchial asthma, hay fever and anaphylactic shock. Suppose cat hair got in the human body with a similar defect in the immune system. When this first happened, nothing unusual allergies do not feel a thing. But in the back of his body will begin the process of sensitization to wool. It will take some time and there will be lots and lots of specific antibodies. The unsuspecting man stroking a cat a second time. And here begins the real allergic reaction.
The fact that the antibodies produced in response to many allergens, there is one very unpleasant property: they like to sit on the cells with biologically active substances. Once again the allergen enters the body, it quickly connects to the ready-made antibodies, already sitting on the cells. As a result, cells starts a chain of biochemical reactions, and they throw out its contents. A large amount of active ingredients, the main one of which is histamine. Histamine is known that fosters the development of an acute inflammatory reaction causes a spasm of smooth muscles (including the muscles of the bronchi), expands the capillaries and reduces the pressure, increases the permeability of
the capillaries and causes swelling.
It also happens
The mechanism of occurrence of allergies, the researchers were able to explain the diversity of its forms. Depending on how the allergen was inorganism, and will manifest allergy. If it has penetrated through the skin, then the person will begin skin problems: swelling, rash, redness, itching. If inhaled — respiratory problems: asthma, runny nose. If the digestive tract: diarrhea, nausea.
In rare cases, an allergic reaction affects the whole body, then begins anaphylactic shock. First the person suffocates or is covered by a rash, then it drops sharply blood pressure. Allergic shock develops rapidly: from the moment of entering the allergen before the reaction takes place from 5 minutes to 3 hours. There can not do without "Ambulance", as if time does not inject epinephrine, can result in death.
It has been almost one hundred years since the emergence of the term "allergy". During this time, an allergy learned almost everything. Remains unclear just one question, the most important one: why the immune system fails, which resulting in allergies?
Doctors shrug and say about the factors that may influence the occurrence of allergy: the impact of solar radiation, poor environmental conditions, stress, uncontrolled use of antibiotics and other drugs, poor diet, sedentary lifestyle. But scientists sadly state that without knowing exactly the root cause of allergies, you can not once and for all get rid of it. You can only treat the symptoms of allergies during exacerbations, making life more bearable allergies.