The mechanism of allergy
More Hippocrates, Avicenna, Galen described cases of intolerance to certain foods resulting in gastrointestinal disorders and urticaria. Allergy has haunted humanity since ancient times, but now allergens have become significantly more because of the deteriorating environmental conditions and the dominance of household, food and industrial chemicals. What is an allergy and why does it occur?
It is well known that the body's immune system protects human health from a wide variety of infections and other external influences. In the body, all the people without exception develop protective proteins - immunoglobulins of several species( A, M, G, E).Immunoglobulins E, which are involved in allergic reactions, usually do not work out very much, for example, they are needed to kill worms.
But it turns out that absolutely all people react to a variety of external stimuli( home dust, household and industrial chemicals, animal hair, pollen of plants and mold) by some increase in the number of immunoglobulins E in the blood.
The need for such an increase is of a guarding nature: immunoglobulin E acts as guard dogs that are thrown at a stranger. In most people this does not cause any external and internal symptoms, as the increase in the number of immunoglobulins E is small. But when the body produces many immunoglobulins E, there are well-known to us allergic reactions.
How does this happen? When substances provoking allergic reactions( allergens) enter the body, immunoglobulins attack them and "grab" along with allergens. Immunoglobulins E sit on membranes of so-called mast cells, inside which various active substances, in particular serotonin, acetylcholine, bradykinin, responsible for the development of inflammatory symptoms, are contained. Histamine is released from the mast cells, and allergic people have swelling of these areas, there is an itch, rash, discharge, for example from the nose. These reactions perform a protective biological function - they expand the vessels and attract other active blood cells to the site, they can also release substances that destroy foreign proteins.
Immunoglobulins are specific when they react only to the definition of an irritant, for example, on pollen of plants or on any food product( eggs, chocolate).
In some diseases, such as hepatitis, AIDS, the amount of immunoglobulins produced in the body may decrease, so allergic symptoms may weaken. But at the same time, a person's immunity to various, often very dangerous infections, sharply decreases, and he becomes practically defenseless before oncological diseases. If you are a true allergic person, you are lucky in the sense that you are unlikely to get sick of another scourge of modern civilization - to get a malignant tumor. Your immune system will not allow this. According to American scientists from the National Cancer Institute, the risk of developing brain tumors is reduced by 33% for % - for various forms of allergy. So, allergy is an increased reactivity of the immune system, arising for various reasons and causing hypersensitivity to a variety of household, food, medicinal and industrial stimuli. They can be both really dangerous and harmful to health( for example, drugs or household chemicals), and completely harmless, but the body still reacts to the intrusion of foreign molecules inadequately.