Allergy ha. Features of an allergic rash

An allergy is an altered reaction of the human immune system to certain substances. In medicine, they are called allergens or antigens. This is an extensive group of active components of household, animal, plant, and industrial origin. The body regards the ingress of antigens as a viral or infectious attack and produces a number of symptoms similar to SARS or influenza. In some cases, development can threaten the patient's life. Sometimes the manifestations of the disease are quite harmless. Why do adults develop allergies? The most common reasons are described in this article.

Reasons why some people are prone to developing allergies

Susceptibility to allergic reactions occurs in connection with the individual characteristics of the body. In some cases, heredity plays a role. As a factor providing a tendency to allergies, low immunity can be distinguished.

The genetic factor is most often passed down through the generation. For example, if a child's grandmother suffered from hay fever, then with a probability of about 60%, by the age of thirty or forty years, he will also become allergic to pollen. The intensity of the manifestations of such a reaction depends on the immune status and general health. Babies born to allergic parents may not suffer from manifestations of a painful reaction to the same provoking factors.

Why does a food allergy occur during pregnancy, and after childbirth it disappears without a trace, as if it had never happened? This process does not occur because of genetics and not because of the weakening of the immune system. The main factor that provokes the development of allergic reactions during pregnancy is a change in the reaction of immune system cells to so-called antigens. They act as antigens and are found in most foods that cause itching, hives, nausea and other manifestations of the disease.

Development of an allergic reaction

All types of the disease, regardless of which antigen they manifested on, proceed according to the same mechanism. All symptoms appear in a strict sequence:

1. immunological stage. It is characterized primarily by the fact that the body begins to produce class E immunoglobulin to the allergen. This process subsequently causes the appearance of a type of reaction - tearing, pruritus, urticaria, etc. At the immunological stage, the beginning of the sensitization process takes place.
2. The pathochemical stage of development Those complexes that had time to form at the immunological stage attack mast cells containing granules capable of activating inflammatory mediators. After that, activated mediators begin to penetrate into every corner of the body through the bloodstream. At this stage, pronounced signs already appear: tearing, itching, urticaria, etc.
3. pathophysiological stage. It is characterized by the fact that mediators that have penetrated and fixed in different tissues of the body initiate allergic processes. Allergy manifests itself in the form and to the extent that we are accustomed to noticing it.

Allergy classification

There are several types of reactions:

1. anaphylactic process. It is also called the immediate type. Why does an allergy occur during an anaphylactic process? The interaction of antibodies (E, G) and immunoglobulins stimulates the production of histamine. It causes the development of allergies. The main representatives of reactions of this type: pruritus, urticaria, anaphylactic shock, allergic rhinitis, Quincke's edema. The anaphylactic process can occur both in the body of an adult and a child.
2. cytotoxic process. Antigens of groups M and G suppress membrane antigens. This is the process of cytolysis. Representatives of allergies in the cytological process: thrombocytopenia, some types of toxic allergies.
3. An immunocomplex allergic reaction in which antibodies of groups M and G are formed. They accumulate on the capillary walls. Subsequently, they inevitably provoke their destruction. Representatives of the immune complex reaction: conjunctivitis, serum reactions, lupus erythematosus, urticaria, some types of dermatitis, hemorrhagic vasculitis.

Why respiratory or respiratory allergies occur

Why does pollen allergy occur? This is the so-called pollinosis. An allergic reaction that belongs to the class Occurs during the flowering period of wormwood, ragweed, poplar and other plants, which most often the human immune system perceives as hostile to its life.

Due to the similarity of pollinosis symptoms, many patients confuse the first manifestations of the disease with bronchitis, tuberculosis and other infectious and inflammatory diseases of the respiratory system. Why is there an allergy to the flowering of certain plants? Because the cells of the human immune system perceive pollen as a threat to the existence of the organism.

Allergens are microscopic. It is not necessary to inhale poplar fluff - a tiny fraction of a poplar seed is enough to provoke symptoms of hay fever. Patients make a common mistake - they think that if they stay in the room, then the manifestations of the disease will not overtake them. In fact, microscopic causative agents of the reaction easily penetrate into the room.

The most common aeroallergens that cause pollinosis:

• pollen;
• spores of some fungi;
• dust mite;
• animal fur.

Why skin allergies occur: dermatoses and urticaria

List of the most common manifestations of allergic reactions on the surface of the skin:

• itching (often so severe that the patient combs the epidermis to the blood);
• small red rashes, popularly called hives, and in the medical world - dermatitis;
• papules - rashes of a relatively large size (up to two mm in diameter) of white color;
• purulent rashes - are formed relatively rarely, most often when exposed to chemical allergens on the surface of the epidermis.

Why do children develop allergies on the skin after they eat sweets? The fact is that most of these products are produced using flavorings, dyes and preservatives. These components often cause the activation of immune cells, which perceive the entry of such substances into the blood as a threat to the life of the organism. As a result, itchy rashes appear on the skin.

Causes of food allergies

Why does food allergy occur? This is a rather complicated process.

Food intolerance in most cases occurs under the influence of two factors:

• allergen characteristics. Hyperreactivity is more often caused by food antigens with high immunogenicity. They freely overcome the barriers of the digestive system. They are highest in cow's milk, red vegetables, some fish, egg whites, cereals, some fruits and nuts. Hypersensitivity of immune cells to the components of these foods and causes skin rashes or itching.
• genetic factors. Allergic manifestations to food products may occur due to an increase in the level of reactivity of immune cells. This process often occurs due to a genetic predisposition.

Allergic reactions to pets

Allergies often become an obstacle to getting a pet. Already on the third or fourth day of cohabitation with a furry friend, intolerance to his coat arises.

Why do you get allergic to cats or dogs? Most often, the reason is that microscopic scraps of animal hair settle on the mucous membrane of the respiratory tract.

You can solve this problem quite simply: get a pet without hair. For example, the Egyptian cat.

List of the most unusual allergens

In some cases, the antigens that provoke the occurrence of unwanted reactions are surprising in their diversity.

A large percentage of patients develop symptoms of the disease when interacting with the following allergens:

• sunlight;
• water;
• touching metal;
• leaves of some trees.

Why does sun allergy occur? Ultraviolet rays are often perceived by the immune cells of allergic people as a dangerous effect that can threaten life. Therefore, there is a rash, itching, swelling of tissues that have been exposed to sunlight. To prevent such a reaction, antihistamines should be taken.

Who is more likely to suffer from allergic reactions: men or women

An allergist or immunologist deals with the treatment of exacerbation of allergies in adults and children. These specialists can prescribe antihistamines that are ideal for each individual patient.

Statistical data, information for which is collected from patients' appeals to allergists, report that both men and women suffer from hay fever approximately equally. But one and a half times more women suffer from manifestations of reactions to taking medications.

Methods for diagnosing allergic reactions

There are the following methods for identifying allergens:

• taking blood for a qualitative sample allows you to find out if there is sensitization to this allergen;
• quantitative blood samples from the patient inform the degree of sensitization.

Blood sampling for analysis is carried out by a standard method. Modern laboratories only need a few drops of venous blood to detect the most likely allergen.

Effective directions for the treatment of allergic reactions

Most patients experience rather unusual manifestations of reactions - for example, an allergy to birch occurs. Why they persecute the patient is not so important. After all, after a course of antihistamines, a person will forget about his problem for a long time.

There are three generations of antihistamine drugs:

• the first generation - with an antihistamine effect (they are cheap, but provoke severe drowsiness);
• second generation - the most optimal drugs with a minimum of side effects;
• third generation - the most modern and safe, but the high cost often becomes an obstacle for the patient to continuous therapy with such drugs.

I have never had a pronounced congenital allergy to anything. Once, at the age of six, I got showered because I overate strawberries - that's all I can tell about my allergic reactions. Some of my acquaintances had allergic reactions to the flowering of certain plants (poplar fluff) already at a mature age, and some of them stopped worrying about allergies after 13 years.

Why does this happen, how to protect yourself from it, is it possible to avoid it and what to do if it is hereditary?

Allergy (ancient Greek ἄλλος - other, different, alien + ἔργον - impact) - hypersensitivity of the body's immune system during repeated exposure to an allergen on an organism previously sensitized by this allergen.

How allergies occur is still not clear.

Scientists have not yet come to a common denominator and cannot say exactly where allergies come from, but the number of people suffering from one form or another of it is growing. Allergens include latex, gold, pollen (particularly ragweed, amaranth, and common cockle), penicillin, insect venom, peanuts, papaya, jellyfish stings, perfume, eggs, house tick feces, pecans, salmon, beef, and nickel.

As soon as these substances start a chain reaction, your body sends its response with a fairly wide range of reactions - from an annoying rash to death. A rash appears, lips swell, chills may begin, stuffy nose and burns in the eyes. Food allergies can cause vomiting or diarrhea. In a very unfortunate minority, allergies can result in a potentially fatal reaction known as anaphylactic shock.

There are medications, but none of them can permanently get rid of allergies. Antihistamines relieve symptoms but cause drowsiness and other not-so-pleasant side effects. There are drugs that really save lives, but they need to be taken for a very long time, and some types of allergies are treated only with complex methods, that is, one medication option is clearly not enough.

Scientists will be able to find a cure that will once and for all save us from allergies, only if they understand the main causes of this disease. But so far they have deciphered this process only partially.

Allergy is not a biological error, but our protection

It is this fundamental question that concerns Ruslana Medzhitova, a scientist who over the past 20 years has made several fundamental discoveries related to the immune system and has received several major awards, including 4 million euros from the Else Kröner Fresenius Award.

For now, Medzhitov is studying a question that could revolutionize immunology: Why do we suffer from allergies? So far, no one has an exact answer to this question.

Medzhitov believes that this is wrong and that allergies are not just a biological error.

Allergy is a defense against harmful chemicals. The protection that helped our ancestors for tens of millions of years and still helps us today.

He admits that his theory is quite controversial, but he is confident that history will prove him right.

But sometimes our immune system harms us.

Healers of the ancient world knew a lot about allergies. Three thousand years ago, Chinese doctors described an "allergic plant" that caused a runny nose in autumn.

There is also evidence that the Egyptian pharaoh Menes died from a wasp sting in 2641 BC.

What is food for one is poison for another.

Lucretius,
Roman philosopher

It was only a little over 100 years ago that scientists realized that such different symptoms could be the heads of the same hydra.

Researchers have discovered that many diseases are caused by bacteria and pathogens, and our immune system fights off these offenders - a whole army of cells that can release deadly chemicals and well-targeted antibodies.

It has also been found that, in addition to protection, the immune system can be harmful.

At the beginning of the 20th century, French scientists Charles Richet(Charles Richet) and Paul Portier(Paul Portier) studied the effect of toxins on the body. They injected small doses of sea anemone venom into dogs and then waited a few more weeks before injecting the next dose. As a result, the dogs went into anaphylactic shock and died. Instead of protecting the animals, the immune system made them more sensitive to this poison.

Other researchers have noted that certain medications have caused rashes and other symptoms. And this sensitivity has developed progressively - a reaction that is the opposite of the protection against infectious diseases that antibodies provide to the body.

Austrian doctor Clemens von Pirquet(Clemens von Pirquet) was studying whether the body can change the body's response to incoming substances. To describe this work, he coined the word "allergy" by combining the Greek words alos (others) and ergon (work).

For the immune system, the allergic process is understandable

In the decades that followed, scientists discovered that the molecular steps of these reactions were remarkably similar. The process was triggered when the allergen appeared on the surface of the body - the skin, eyes, nasal passage, throat, respiratory tract or intestines. These surfaces are filled with immune cells that act as border guards.

When the "border guard" encounters an allergen, he absorbs and destroys the uninvited guests, and then supplements its surface with fragments of the substance. The cell then localizes some of the lymphatic tissues, and these fragments are passed on to other immune cells, which produce specific antibodies known as immunoglobulin E or IgE.

These antibodies will elicit a response if they encounter the allergen again. The reaction will begin immediately after the antibodies activate the components of the immune system - mast cells, which cause a flurry of chemicals.

Some of these substances can catch on nerves, causing itching and coughing. Sometimes mucus starts to be produced, and contact with these substances in the respiratory tract can cause breathing problems.

This picture has been painted by scientists for the last century, but it only answers the question "How?", and does not explain at all why we suffer from allergies. And this is surprising, since the answer to this question is clear enough for most parts of the immune system.

Our ancestors were exposed to pathogens, and natural selection left mutations that helped them fend off these attacks. And these mutations are still accumulating so that we can give a worthy rebuff.

Seeing how natural selection could create an allergy was the hardest part. A strong allergic reaction to the most harmless things was hardly part of the survival system of our ancestors.

Also, allergies can be rather strangely selective.

Not all people are prone to allergies, and only some substances are allergens. Sometimes people develop allergies at a fairly adult age, and sometimes childhood allergies disappear without a trace (we say “outgrown”).

For decades, no one really understood what IgE was for at all. He did not show any special abilities that could stop a virus or a bacterium. It's more like we evolved to have one particular kind of antibody give us a huge problem.

The first clue came to us in 1964.

During the internship, Medzhitov studied the theory of worms, but after 10 years he began to have doubts. According to him, this theory did not make sense, so he set about developing his own.

He mainly thought about how our bodies perceive the world around us. We can recognize photon patterns with our eyes and the pattern of air vibration with our ears.

According to Medzhitov's theory, the immune system is another pattern recognition system that recognizes molecular signatures instead of light and sound.

Medzhitov found confirmation of his theory in the work Charles Janeway(Charles Janeway), Immunologist at Yale University (1989).

Advanced immune system and overreacting to invaders

At the same time, Janeway believed that antibodies have one big drawback: it takes several days for the immune system to develop its own response to the aggressive actions of a new invader. He suggested that the immune system may have another line of defense that works faster. Perhaps she can use a pattern recognition system to detect bacteria and viruses faster and start fixing the problem faster.

After Medzhitov's appeal to Janeway, the scientists began to work on the problem together. They soon discovered a new class of sensors on the surface of certain types of immune cells.

When confronted with invaders, the sensor wraps around the intruder and sets off a chemical alarm that helps other immune cells find and kill the pathogens. It was a fast and accurate way to recognize and eliminate bacterial invaders.

So they discovered new receptors, now known as toll-like receptors, which showed a new dimension in immune defense and which were proclaimed a fundamental principle of immunology. It also helped solve the medical problem.

Infections sometimes lead to catastrophic inflammation throughout the body - sepsis. In the United States alone, it strikes millions of people every year. Half of them die.

For years, scientists believed that bacterial toxins could cause the immune system to malfunction, but sepsis is just an exaggerated immune defense against bacteria and other invaders. Instead of acting locally, it turns on a line of defense throughout the body. Septic shock is the result of these defense mechanisms being activated much more strongly than the situation actually requires. The result is death.

Home alarm system for the body that gets rid of allergens

Despite the fact that initially Medzhitov was not engaged in science in order to treat people, the discoveries made by him allow doctors to take a fresh look at the mechanisms that trigger sepsis, and thus find an appropriate treatment that will be aimed at eliminating the real cause of this disease - overreaction of toll-like receptors.

The more Medzhitov thought about allergens, the less important their structure seemed to him. Perhaps what binds them is not their structure, but their actions?

We know that very often allergens lead to physical damage. They tear open cells, irritate membranes, tear proteins to shreds. Perhaps allergens are causing such great harm that we need to protect ourselves from them?

When you think about all the main symptoms of an allergy - stuffy red nose, tears, sneezing, coughing, itching, diarrhea and vomiting - they all have one common denominator. They are all like an explosion! Allergy is a strategy for ridding the body of allergens!

It turned out that this idea has been floating on the surface of various theories for a long time, but every time it is drowned again and again. Back in 1991, evolutionary biologist Margie Profe(Margie Profet) claimed that allergies fought toxins. But the immunologists dismissed the idea, perhaps because Profe was an outsider.

Medzhitov, with two of his students Noah Palm and Rachel Rosenstein, published their theory in Nature in 2012. Then he started testing it. First, he tested the link between injuries and allergies.

Medzhitov and colleagues injected mice with PLA2, an allergen found in bee venom (it ruptures cell membranes). As Medzhitov predicted, the immune system did not specifically respond to PLA2 at all. It was only when PLA2 damaged the exposed cells that the body began producing IgE.

Another suggestion by Medzhitov was that these antibodies would protect the mice, not just make them sick. To test this, he and his colleagues gave a second injection of PLA2, but this time the dose was much higher.

And if the animals had practically no reaction to the first dose, then after the second dose the body temperature rose sharply, up to a lethal outcome. But some mice, for reasons not entirely understood, built up a specific allergic reaction, and their bodies remembered and reduced their exposure to PLA2.

At the other end of the country, another scientist was doing an experiment, which as a result further confirmed Medzhitov's theory.

Stephen Galli, chair of the pathology department at Stanford Medical University, has spent years studying mast cells, mysterious immune cells that can kill people in an allergic reaction. He suggested that these mast cells could actually help the body. For example, in 2006, he and his colleagues discovered that mast cells destroy a toxin found in snake venom.

This discovery led Galli to think the same thing that Medzhitov thought - that allergies could actually be a defense.

Galli and his colleagues carried out the same experiments with mice and bee venom. And when they injected mice that had never previously been exposed to this type of poison with IgE antibodies, it turned out that their bodies received the same protection against a potentially lethal dose of poison as mice exposed to this toxin.

Until now, despite all the experiments, many questions remain unanswered. How exactly does the damage caused by bee venom lead to a protective IgE response, and how did IgE protect the mice? These are exactly the issues that Medzhitov and his team are currently working on. In their opinion, the main problem is mast cells and the mechanism of their work.

Jamie Cullen(Jaime Cullen) studied how IgE antibodies fix mast cells and cause them to become sensitive or (in some cases) hypersensitive to allergens.

Medzhitov predicted that this experiment would show that allergen detection works like a home alarm system. In order to understand that a thief has climbed into your house, it is not at all necessary to see his face - a broken window will also tell you about this. The damage caused by the allergen awakens the immune system, which collects molecules in close proximity and produces antibodies to them. Now the intruder has been identified and next time it will be much easier to deal with him.

Allergies seem much more evolutionarily logical when viewed as a home alarm system. Toxic chemicals, whether they come from poisonous animals or plants, have long been a threat to human health. Allergies were supposed to protect our ancestors by flushing these substances out of the body. And the discomfort that our ancestors felt as a result of all this may have forced them to move to safer places.

Allergies have more advantages than disadvantages

Like many adaptation mechanisms, allergies are not perfect. It reduces our chances of dying from toxins, but still does not completely eliminate this risk. Sometimes, due to a too sharp reaction, an allergy can kill, as has already been the case in experiments on dogs and mice. However, the benefits of allergies outweigh the disadvantages.

This balance has shifted with the advent of new synthetic substances. They expose us to a wider range of compounds that can potentially cause damage and trigger an allergic reaction. Our ancestors could have avoided allergies simply by going to the other side of the forest, but we cannot get rid of certain substances so easily.

Over the next few years, Medzhitov hopes to convince skeptics with the results of other experiments. And this could possibly lead to a revolution in how we think about allergies. And he starts with a pollen allergy. Medzhitov does not hope for a quick victory for his theory. For now, he is just happy that he manages to change people's attitude to allergic reactions and they stop perceiving it as a disease.

You sneeze, which is good, because in this way you protect yourself. Evolution doesn't care how you feel about it.

The World Health Association has already called our century the century of allergies: the number of allergy sufferers is growing every year, both among children and adults. How to recognize allergies by symptoms?

What is an allergy

According to some estimates, every fourth person in the world suffers from allergies. So everyone knows about allergies, even those lucky ones who have never experienced allergic reactions from personal experience. The main signs of an allergy are familiar to everyone: runny nose, sneezing, skin rash.

An allergy is an atypical reaction of the body to a certain substance. This substance may be completely harmless to others, but the allergic person's immune system recognizes it as hostile and declares war on it.

Excessive activity of the immune system pretty much spoils the life of allergy sufferers, but it also prolongs this very life. Scientists have found that allergy sufferers are less likely to get cancer. A vigilant immune system is more likely to recognize a tumor in the bud and get rid of it with the resources of the body.

Allergy Mechanism

If our immune system protects us, then why does it go sideways to us? Why does an allergic person feel itchy or get a rash? The reason is the entry into the blood of mediators (transmitters) of allergic reactions, such as histamine. These mediators are part of some cells and are usually in an inactive state. However, when an allergen enters the body of an allergic person and the immune system attacks it with antibodies, the cells are damaged, releasing mediators of allergic reactions.

Nicotine is a powerful histamine releaser. Therefore, in smokers, allergy symptoms are more pronounced.

Histamine and other mediators cause spasm of the muscles of the bronchi, vasodilation, lowering blood pressure, increased secretion of gastric juice and tissue edema. All these processes are the underlying causes of allergic symptoms.

Types and symptoms of allergies

Respiratory allergy manifests itself in violation of the respiratory system. The first signs of a respiratory allergy are nasal discharge and itching in the nose, throat, and ears. There may also be frequent sneezing and coughing.

The most common pathogen is, of course, the pollen of plants - birch, poplar, wormwood, quinoa, etc. Pollen allergy is scientifically called pollinosis, and in the old way - hay fever, because it was once believed that it was associated with hay.

Other causative agents of respiratory allergies are animal hair and dust, or rather, dust mites and their waste products. Dust mites live in upholstered furniture, carpets, pillows, bedding and clothes.

If your child regularly sneezes or coughs from dust, don't brush it off as something unimportant. If the signs of allergies in children are ignored, then innocent sneezing can develop into.

This allergy annoys both children and adults. Skin allergies are usually a reaction to food and household chemicals, such as washing powder, soap, shampoo. So, if you find that the skin on your child's body turns red from time to time, try changing the detergent.

Cosmetics also often cause allergic reactions. To avoid becoming a beauty victim, follow the instructions for use, do not leave the product on the skin longer than it should be, and never use expired cosmetics.

The main signs and symptoms of a skin allergy are skin peeling, redness, and a rash. A specific infantile symptom of skin allergies is diaper rash of the buttocks and armpits.

Skin allergies come in many varieties. Adults are more likely to suffer from eczema, and children are more likely to suffer from urticaria and atopic dermatitis. However, the signs of allergies in children and adults are almost the same.

Urticaria manifests itself in the form of blisters, similar to those that come from a nettle burn. Atopic dermatitis in children develops against the background of diathesis and looks like a red rash on the cheeks and body of the baby. Atopic dermatitis often develops at 3-4 months of age due to a change in diet. For example, many parents notice signs of allergies in their children after switching to milk protein formulas. Therefore, pediatricians recommend, if possible, continue breastfeeding for at least six months.

food allergy

Food allergy manifests itself in intestinal upset. Its causative agents are food, for example, milk, nuts, fish, fruits and berries, especially red. The first symptoms of an allergy of the digestive system are itching in the mouth and swelling of the tongue and mucous membranes. If nothing is done, more severe symptoms follow: vomiting, colic, constipation, diarrhea. Food allergies can be accompanied not only by intestinal problems, but also by skin manifestations: a rash and redness.

Other types of allergies
Each of the allergic varieties listed above had its own specific symptoms. But there are allergies that can manifest a whole range of symptoms - from rashes to choking and from vomiting to swelling.

drug allergy

Allergy to drugs is considered the most dangerous: sometimes it leads to anaphylactic shock. It is accompanied by swelling of the airways, vomiting, low blood pressure and can be seriously life-threatening. However, it should be noted that anaphylactic shock can be a reaction not only to medications, but also to food or insect bites.

But, fortunately, it comes to anaphylactic shock relatively rarely. Other signs of drug allergy are much more common. They generally coincide with symptoms of respiratory (rhinitis), skin (urticaria, itching, redness, rash) or food (colic, vomiting) allergies.

The most common drug allergens are salicylic acid, penicillin antibiotics and analgesics.

Psychological allergy

Despite the fact that in the physiological sense, an allergy is a reaction to the effects of a substance, sometimes an allergic reaction can be a manifestation of acute emotional experiences.

For example, an allergy to oranges may not be related to the chemical composition of the fruit, but to unpleasant emotions that a person once experienced and which are subconsciously associated with oranges. For example, he ate fruit when he was informed of some kind of trouble. Apparently, such incredible reactions as are associated with psychology.

It is impossible to cure allergies once and for all. Moreover, there are cases when an allergic reaction is provoked by a substance that for many years before was not perceived by the body as a threat.

But we hasten to please you: everything is far from hopeless. Although it is impossible to remake the immune system, it is quite possible to eliminate the symptoms of allergies.

Allergy symptoms in adults may be less pronounced than in children, so allergies are often confused with other diseases, such as a cold. Therefore, at the slightest suspicion of an allergy, consult your doctor. The sooner you start defending, the better.

Allergy is a disease that, to one degree or another, covers almost the entire body.

This is because the cells involved in the formation of the immune response are located in different tissues.

Therefore, how exactly the disease manifests itself depends on many factors.

Allergy symptoms are influenced by the state of the person himself, the type of protein that caused the pathological reaction, and the way it affects the body (inhalation, contact or food).

Skin manifestations are noted in almost a quarter of patients.

These diseases are called allergic dermatoses, this group includes:

• atopic dermatitis, including neurodermatitis;
• contact dermatitis;
• angioedema;
• skin lesions associated with the use of certain drugs.

Epidermal signs of allergy can be the result of exposure to both endogenous causes and external factors, such as sun exposure, high or, conversely, low ambient temperature, mechanical pressure, friction, etc. Clinical manifestations of pathology are also different. For some, it can be intense skin itching, for others it can be a feeling of tightness of the skin, pain and burning.

However, regardless of the etiology, all allergic dermatoses are accompanied by sleep disturbance, general condition disturbance, decrease or complete loss of working capacity, which significantly affects the quality of life.

Atopic dermatitis

As a rule, this disease occurs in children at an early age. The appearance of symptoms of pathology is primarily due to hereditary predisposition. During atopic dermatitis, several periods are distinguished: infant (up to 2 years), children (from 2 to 13 years), adolescent and adult (from 13 years and older). Moreover, each of the stages has its own distinctive signs of allergy.

According to the prevalence of the process, the disease can be limited-localized, when the elbow and popliteal folds, the skin of the hands, and the face are affected. The area of ​​precipitation does not exceed 10%. With widespread atopic dermatitis, the chest, back, neck and remaining skin of the extremities are involved in the pathological process. The area of ​​damage is from 10 to 50% of the epidermal cover. In the diffuse form of the disease, symptoms appear on more than half of the body.

Clinical symptoms of atopic dermatitis depend on the age stages. In the first, infantile period, the development of hyperemia, swelling and crusting is noted. Lesions are usually localized on the face and on the outer surface of the legs. Over time, it spreads to the flexion and extensor areas of the limbs, mainly in the folds of large joints (knee and elbow), as well as in the wrist and neck.

In the second, childhood age period, the signs of allergy are not so acute, but acquire a chronic course. In the elbow and popliteal folds, on the back of the neck, on the fold of the ankle and wrist joints, in the ear region, erythema (usually with a bluish tint), papules, areas of peeling and infiltration, covered with cracks, are formed. In some children, an additional fold of the eyelid is formed.

In the third period, the papules merge into foci of cyanotic infiltration. The selectivity of rashes in the area of ​​the upper half of the trunk, face, neck and arms is characteristic.

For the treatment of this type of dermatitis, doctors often prescribe the drug Dupilumab.

Hives

Allergy symptoms of this genesis can make themselves felt both in adults and in children. The main clinical manifestation of urticaria is the formation of blisters due to increased vascular permeability. Usually the formation of papules is accompanied by:

• skin itching, less often - burning;
• limited swelling;
• redness.

Unlike atopic dermatitis, these symptoms can appear anywhere on the skin. In about half of the cases, urticaria is accompanied by Quincke's edema.

Allergic contact dermatitis

The disease proceeds in the form of the formation of small itchy vesicles with areas of redness at the site of direct contact with allergens. At the initial stage of the pathology, signs of allergy appear at high concentrations, but over time, after the end of the sensitization period, such symptoms develop even with minimal contact with the irritant.

Upon contact of the allergen with the mucous membrane of the upper and lower respiratory tract, specific symptoms from the respiratory tract occur, associated with increased activity of the cells of the mucous epithelium. In this case, the organs of vision are usually affected - allergic conjunctivitis occurs.

The reasons for such phenomena are:

• inhalation of pollen from certain plants (hay fever), which occurs more often in spring and summer;
• excessive accumulation of dust;
• increased sensitivity of the immune system to fungal spores (for example, mold);
• an allergic reaction to the hair of cats, dogs and other pets, bird feathers, the smell of fish food;
• inhalation of tobacco smoke and other toxic fumes.

It can occur year-round or at certain times of the year, which is combined with the flowering period of plant allergens (loboda, nettle, ambrosia, alder, etc.). The main symptoms of this type of allergy are manifested in the form of itching, burning and tickling in the nose, copious secretion of mucus and associated nasal breathing disorders. Such a picture is usually accompanied by a neurosis-like syndrome: tearfulness, insomnia, irritability. Often patients complain of dizziness, mild nausea and headache.

Bronchial asthma

The main reasons for its occurrence are called prolonged exposure to plant, animal allergens and other substances of organic and inorganic origin. The main symptoms of allergies associated with bronchial asthma are severe coughing attacks, accompanied by suffocation, wheezing.

They can occur spontaneously, but more often at night. With increased sensitivity to inhalation irritants, exacerbation of the disease is preceded by manifestations of allergic rhinitis or conjunctivitis. The frequency of attacks largely depends on the severity of asthma. Mepolizumab-based drugs are used to treat this disease.

The disease occurs with inflammation of the pulmonary alveoli without involvement of the bronchial tissue in the pathological process. The main cause of the pathology is the inhalation of complex fine dust containing particles of insects, plants, bacteria, sawdust, wool, excrement and skin of animals, spores of saprophytic fungi.

Allergy symptoms depend on the severity of the disease. In the acute form of the pathology in the afternoon, the body temperature rises, a paroxysmal cough occurs, accompanied by wheezing in the lungs.

After a few days, the bronchi are also involved in the pathological process, as a result, the symptoms resemble the clinical picture of pneumonia or bronchitis.

The subacute course of the disease is accompanied by the occurrence of shortness of breath against the background of strong physical exertion a few days after contact with the allergen. The chronic form of the pathology occurs only with short episodes of shortness of breath, which does not correspond to the intensity of muscle training.

Allergic laryngitis

The main symptoms of an allergy affecting the mucous membrane of the larynx are associated with bouts of barking, choking cough. It is accompanied by perspiration, irritation and sore throat, which are aggravated by swallowing. Often there is hoarse shortness of breath. The most dangerous allergic laryngitis for children, as swelling of the mucosa at an early age prevents normal breathing.

Very often manifestations from the respiratory tract are accompanied by allergic conjunctivitis. Its main symptoms are lacrimation, photophobia, severe hyperemia of the inner side of the lower eyelid. A person is constantly worried about the sensation of a foreign body in the eye and the itching associated with it. Often, allergic conjunctivitis is complicated by an attached bacterial infection due to the ingress of pathogenic microorganisms from the hands.

Food allergy is comparable in prevalence to neurodermatosis and manifestations from the organs of the respiratory system. Its main cause is the contact of the irritant with the mucous membrane of the gastrointestinal tract, in other words, when certain foods are consumed.

And it is the signs associated with the characteristics of the diet that in most cases are systemic in nature and affect a variety of internal organs and even the vascular wall. Most often, such manifestations are caused by cow's milk protein, especially at an early age as part of various mixtures for artificial feeding, eggs, chocolate, citrus fruits and other products.

Usually, food allergy manifests itself in the form of urticaria with predominant localization in the face, abdomen, inner surface of the limbs, buttocks. Often noted manifestations of the gastrointestinal tract in the form of dyspeptic syndrome. In severe cases, signs of allergy affect the inner wall of blood vessels, which is accompanied by hemodynamic disturbances, pain impulses in muscles and joints.

But the most severe and life-threatening symptoms of a pathological reaction are Quincke's edema and anaphylactic shock. In the vast majority of cases, Quincke's edema (also called angioedema) develops against the background of urticaria, and the reasons for its appearance are similar. However, unlike allergic dermatitis, it practically does not cause external manifestations from the epidermis.

There is a sharp swelling of the mucous membranes in the mouth, neck and face. Due to the narrowing of the lumen of the respiratory tract, respiratory function deteriorates sharply, which can cause fainting and even death. Quincke's edema rarely affects the organs of the gastrointestinal tract, which is accompanied by pain, diarrhea, and vomiting. And only in isolated cases, the pathology covers the meninges, it is extremely dangerous and fraught with irreversible changes in the cells of the central nervous system.

Anaphylactic shock refers to allergic reactions of the immediate type. Its symptoms develop within a few minutes after contact with the irritant. Blood pressure drops sharply, diffuse pallor with a bluish tint appears.

Anaphylactic shock can proceed in this way:

• with a predominant lesion of the skin in the form of diffuse urticaria and edema;
• with oppression of the nervous system, in this case, headache, hot flashes, convulsions, involuntary excretion of urine and feces, fainting are noted;
• with an effect on the respiratory system, due to mucosal edema, coughing attacks occur, accompanied by suffocation, in general, the clinical picture resembles signs of allergies in bronchial asthma;
• with damage to the heart muscle, in this case, symptoms of acute edema and myocardial infarction occur.

Allergy symptoms in adults and children, clinical varieties of the disease

Doctors say that age does not affect the severity of the clinical manifestations of an allergic reaction. Moreover, some forms of the disease are easier in children.

Ultimately, the intensity of the symptoms of pathology depends on the genetically determined characteristics of the human immune system.

Allergy symptoms in children and adults also significantly affect the duration of treatment. Hypersensitivity to pet hair particles is usually accompanied by nasal, ocular, and skin symptoms.

The exact lesions depend on the location of the allergen contact, in other words, when the irritant is inhaled, rhinorrhea, swelling of the epithelium of the nose and mouth, lacrimation, coughing and sneezing are noted. Contact dermatitis is characterized by the appearance of a rash when touched by a pet.

Allergic reaction to cold, is accompanied by the appearance of papules, itching and redness of exposed skin areas, and signs of allergy in adults and children can also develop upon contact with cold water, snow, ice.

food allergy. This form of the disease is characterized by a clear relationship between the consumption of certain foods and the development of symptoms. Usually there are itchy rashes on the skin, much less often (in particular, against the background of pathologies of the gastrointestinal tract), systemic reactions appear in the form of digestive disorders.

Contact form of the disease in response to chemical and household stimuli. Usually, the signs of children are limited to a local skin reaction in direct contact with detergents and cleaning agents, a variety of substances during professional activities. There is a characteristic rash, often it is accompanied by severe pain, hyperemia, dry skin.

drug allergy belongs to the most severe forms of the disease, as it is often unpredictable. So, the most dangerous in terms of clinical manifestations is the intravenous administration of the drug. However, an immune response can also occur with the intramuscular use of the drug, as well as with its local application or in the form of tablets, but in this case, the signs of allergy are not so acute. Characterized by the appearance of urticaria, angioedema, contact dermatitis. Sometimes a diffuse lesion of the skin is also noted with the formation of areas of necrosis, metabolic disorders, fluctuations in blood pressure, and a change in heart rate.

For allergic reaction to alcohol characteristic manifestations typical of food hypersensitivity in the form of rashes, edema, coughing and asthma attacks. According to doctors, such allergy symptoms in adults appear in response to alcohol exposure.

Pathological reaction to sweets and flour products can be caused by gluten, which is part of wheat or rye flour. Sometimes similar symptoms occur with increased sensitivity to mold, which is formed during improper storage of products. Signs of allergy in children to flour products usually appear at an early age and are of a “classic” nature for a food reaction (rashes, diarrhea, discomfort in the stomach and intestines).

Allergy: signs and symptoms, diagnosis, treatment and prevention

Regardless of the cause of the pathological activity of the body, doctors prescribe tests to assess the general condition of the immune system. Determine the concentration of immunoglobulins, the reaction of mast cells, basophils and eosinophils in response to contact with an irritant. A comprehensive examination of a person is also necessary to exclude possible concomitant pathologies.

Allergy signs and symptoms may overlap with other systemic diseases, so it must be definitively confirmed in order to conduct further research. Specific are tests to assess the body's response to a particular stimulus.

Roughly speaking, a specific antigen is administered subcutaneously, sublingually or intranasally. Sometimes a food allergy patient is simply told to eat the food that is suspected to be the cause of the symptoms. After that, an assessment of the human condition is carried out: the development of dermatosis, edema, fluctuations in blood pressure, pulse, etc.

The basis of allergy treatment are antihistamines (Erius, Claritin, Zirtek, etc.). Some of them can be used starting from six months of age. With long-lasting signs of rhinitis and conjunctivitis, intranasal corticosteroids are prescribed. Allergies, the signs and symptoms of which are most severe, require hormones in the form of tablets.

However, almost all of these drugs are contraindicated during pregnancy.. Therefore, when planning a conception, a woman predisposed to a hypersensitivity reaction is recommended to undergo a course of specific vaccination. A special approach is required for life-threatening conditions - Quincke's edema and anaphylactic shock. In such a situation, antihistamines will be useless, since the effect of their use does not develop quickly enough. The patient is injected with a solution of adrenaline or dexamethasone.

If the signs and symptoms of an allergy appear only upon direct contact with an irritant, it requires constant adherence to the rules of prevention. Its main principle is to avoid the effects of the allergen on the body as much as possible. In addition, people with a predisposition to such diseases should follow a certain diet, if possible, protect the skin from cold and direct sunlight, and regularly clean the room from dust.