Atopic dermatitis - what is it, how is it recognized and treated?

Atopic dermatitis is a chronic allergic disease with periods of exacerbation and remission. The most characteristic symptoms of the disease are persistent itching of the skin and red lesions that resemble lichen. Atopic dermatitis is most often diagnosed in young children; adults get sick less often.

Other terms for atopic dermatitis, such as atopic eczema or formerly used scabies, bring together the nature and specific symptoms of this disease in the name itself. People suffering from AD suffer from chronic itchy skin. Scratching that is difficult to control causes the skin to break down, weakening its protective barrier function. As a result, there is an excessive loss of water from the deeper layers of the skin (drying out), and allergens have a greater chance of entering the body.

What is atopy?

The content of the article

Atopy is an abnormal response of the body to an allergen, resulting in overproduction of IgE antibodies responsible for the allergic reaction. Atopic dermatitis belongs to the group of atopic diseases, like bronchial asthma, urticaria and hay fever.

Patients prone to atopy usually have several allergic diseases at the same time. The body of a person with AD responds to very low doses of allergen (molecules that can trigger an immune response) in the environment. The disease can be caused by many factors that surround us: dust mites, pollen from flowers, animals and food.

Causes of atopic dermatitis

The first symptoms of atopic dermatitis in almost half of patients appear between the third and sixth months of life, in most cases the disease appears before the age of five. The origin of atopic dermatitis is complex and its development is a combination of environmental, genetic, immunological and non-immunological factors.

In AD patients, there is a genetic defect in the epidermis that causes abnormalities in the composition of the superficial layer of the skin. As a result, the patient's skin is overexposed to allergens and becomes dry, overly sensitive and itchy.

Atopic dermatitis

The disease is genetic, which means that if one or two parents had atopic dermatitis or any other atopic disease, the likelihood of children inheriting a tendency to atopy, including atopic dermatitis, is high.

How to avoid worsening dermatitis in winter

In winter, exacerbation of dermatitis is common. Even healthy skin can have a hard time coping with temperature changes and dry indoor air. The following will help you get rid of the symptoms of the disease even in the frosty months:

• cold compresses,
• warm baths with oatmeal or baking soda,
• creams or ointments for the body with a high concentration of oils in the composition (apply the cream immediately after a bath or shower).

In winter, it is especially important to try not to irritate the skin, do not rub it with a towel, avoid scratches, and do not use cosmetics with fragrances (Fig. 4). When cleaning, be sure to wear gloves and goggles when using aerosol cleaners. In clothing, preference should be given to soft, natural fabrics, such as cotton. Thus, during the cold season, the daily routine should be even more gentle than usual.

Figure 4. How to care for skin with eczema in winter. Illustration: MedPortal

What are the symptoms of atopic dermatitis (AD)?

The most common symptom of atopic dermatitis is eczema, an inflammation that appears as papules on reddened skin. Skin lesions usually appear in groups and in irregular shapes.

Scratching causes damage to the skin. Chronic lesions lead to lichenification (thickening) of the skin and its hyperkeratosis, that is, ichthyosis (keratosis pilaris, ichthyosis). In very severe conditions, erythrodemia may occur, that is, general inflammation of the skin, enlarged lymph nodes and fever.

Depending on the age of the patient, the course of the disease can be divided into three phases: childhood, adolescence, and adulthood. The location of changes differs from time to time. In children, symptoms of atopic dermatitis are often visible on the cheeks and forehead, while in adults it is mainly visible in the flexures of the lower and upper limbs. In addition, adults may develop other symptoms of AD, such as whitish dandruff, which does not occur in children.

The concepts of “dermatitis” and “eczema” in the history of dermatovenerology have undergone dynamic development due to the expansion of our knowledge in related branches of medicine (for example, allergology). However, to date there is no unambiguous understanding of the differences between these diseases, since there is no clear definition and classification of them. Despite the rapid development of allergology, outdated concepts continue to dominate in dermatovenerology.

Some authors identify the content of the terms “eczema”, “atopic dermatitis”, “allergic eczema”, “disseminated neurodermatitis”, “prurigo” and the terms “lichenification”, “eczematoid dermatitis”, “food” and “infantile eczema”, etc. .

Due to the transition of healthcare to insurance medicine, terminological confusion does not allow assessing the quality of medical care and, therefore, needs serious correction.

A.I. Pospelov gives the following definition of eczema: “Eczema is an inflammatory skin disease, in most cases not contagious and usually occurring chronically, less often acutely.” In a later work, A.I. Pospelov, calling eczema “weeping lichen,” gives the following definition: “Eczema currently means superficial inflammation of the skin, accompanied by redness, swelling, fever, the appearance of scattered nodules and blisters, weeping or peeling , a feeling of tension, burning and significant itching." The author further divides eczema into acute and chronic. Describing the course of eczema, he writes: “If you cause artificial inflammation on a person’s skin by lubricating the skin, for example, with turpentine or another substance, subjecting it to friction or elevated temperature, then a few hours after this, at the site of irritation, the skin will turn red and swell (edema) , its local temperature will rise and the affected area will “burn” or itch - this will be eczema erythematozum.” In our opinion, the described clinical picture corresponds to simple contact dermatitis, but not eczema, which indicates the existence of discrepancies even among such a famous dermatologist as A.I. Pospelov.

According to the definition of V. Duperrat (1959): “Eczema is the most common skin reaction to extremely small external or internal influences (which are not all known yet), a reaction that during its development represents, first of all, a complex of dermal-epidermal lesions, among which spongiosis with vesiculation predominates.”

Even in modern clinical recommendations for dermatovenereology, the division of eczema into acute and chronic dominates: “Eczema (from the Greek Ekzeo - I’m boiling) is an acute, less often chronic, recurrent allergic disease, characterized by the appearance of a polymorphic rash, severe itching and an acute inflammatory reaction caused by serous inflammation of the skin.” .

Dr. Max Joseph, citing the experiments of Hebra, who, by rubbing croton oil into a healthy area of ​​the skin, received “... a number of clinical phenomena that in many respects were similar to the phenomena observed in acute eczema. This proved that irritation acting on the skin can cause various clinical forms of the disease." He also divides eczema into acute and chronic and gives six stages of development of acute eczema: erythematous, papular, vesicular, oozing, impetiginous and squamous." Thus, the polymorphism of rashes is considered as pathognomonic signs of acute eczema, while chronic eczema is recognized not by the duration of the process, but by the changes that remain as a result of the development of the disease: “In chronic eczema, persistent changes in the skin, dense impregnation, cracks and etc.” .

G.I. Meshchersky attributed eczema to a skin syndrome, “... which at the height of development is characterized by edematous erythema with tiny, poppy seed-like, transparent blisters filled with a pale yellow sticky liquid, superficial, i.e. located directly under the stratum corneum."

A.I. Kartamyshev understood eczema as: “Itchy, often located in symmetrical areas, superficial inflammation of the skin, which is characterized by the appearance of nodules and blisters, often turning into erosions or crusts and healing with the formation of scales without leaving permanent changes in the skin. ...Eczema is characterized by polymorphism of the primary and secondary elements of the rash, a tendency to relapse, and a feeling of itching that always accompanies the disease.”

M.M. Zheltakov defined eczema as an allergic disease, which is characterized by a rash of blisters, weeping and a chronic relapsing course. Speaking about allergic dermatitis, M.M. Zheltakov cited the name “Eczematous dermatitis” as a synonym, thereby emphasizing the similarity of clinical manifestations.

O.L. Ivanov et al. distinguish “allergic dermatitis” and “toxidermia”, apparently implying “contact allergic dermatitis” by allergic dermatitis. They note that the clinical picture of allergic dermatitis is similar to the acute stage of eczema. It is also indicated here that the differential diagnosis of allergic dermatitis is carried out with eczema, which is characterized by polyvalent (rather than monovalent) sensitization and a chronic relapsing course, with toxicoderma, in which the allergen is introduced into the body. Describing the treatment of toxicoderma, the authors write: “With fixed toxicoderma, they are limited to the use of local anti-inflammatory and, if necessary, antiseptic agents...”. It is not clear what kind of fixed toxicoderma we are talking about; apparently, contact allergic dermatitis is again implied. At the same time, citing the formulation of eczema, the authors indicate: “Eczema is a common chronic recurrent skin disease of allergic origin, characterized by polyvalent sensitization and a polymorphic itchy rash (vesicles, erythema, papules).”

B.I. Karuna believes that eczema occurs acutely, subacutely and chronically, and divides eczema into true, or idiopathic, microbial, occupational, seborrheic, and childhood.

N.A. Torsuev et al. write: “Dermatitis is a common inflammatory reaction of normally responsive skin to external and internal harm. Eczema is a dermatitis in a predisposed subject; it is a special form of intolerance reaction. Thus, as H. Fuchs and L. Kumer correctly note, every eczema is dermatitis, but dermatitis is by no means eczema.” Further, the authors propose: “... the concept of allergic or eczematized dermatitis should be removed as completely unfounded and unnecessary and a strict distinction between the concepts of “dermatitis” and “eczema” should be adhered to (unfortunately, it is not specified which dermatitis we are talking about).

Literary references can be continued, but a brief excursion into the history of the issue allows us to conclude that scientists are divided into two groups: those who separate the concepts of allergic dermatitis and eczema and those who mix them up.

If we analyze the chronology of changes in ideas about dermatitis and eczema, the following pattern can be traced. At a time when there was no knowledge about allergic processes, the concept of “allergic dermatitis” naturally did not exist. With the development of allergology, a division of dermatitis into “simple contact” and “allergic” appeared. Despite the accumulated knowledge of the pathogenesis of allergic dermatoses and the inclusion of eczema in the group of these diseases, a clear separation of eczema from allergic dermatitis has not occurred.

In the protocols for the management of patients, eczema is interpreted as “a chronic recurrent acute inflammatory polyetiological disease with pronounced polymorphism of the elements of the rash,” and toxicdermia is “an acute inflammatory lesion of the skin and often mucous membranes, resulting from exposure to toxic, allergic, toxic-allergic agents introduced into the body ( inhalation, oral administration, parenteral administration). The clinical picture is distinguished by the polymorphism of the rashes (spots, papules, urticaria, vesicles, etc.).” As can be seen from the above definitions, the difference between the two diseases is only in the duration of their course, but there is no semantic meaning in the phrase “chronic recurrent acute inflammatory disease.” You can understand that eczema throughout the entire illness is an acute inflammatory dermatosis, but this is far from the case.

The definition of toxicerma also leaves much to be desired. In the standards for the provision of specialized medical care in the section: “Diseases of the skin and subcutaneous tissue” for nosologies, including allergic dermatoses, atopic dermatitis is presented; dermatitis, unspecified (true eczema); dermatitis caused by substances taken orally (toxidermia); hives. The standards do not provide a definition of nosological units, while true eczema is equated to “unspecified dermatitis.”

It seems to us necessary to improve the classification of dermatitis and eczema, because (as already indicated) insurance medicine is unthinkable without a basic focus on quality standards of medical care.

Taking into account the above literature review and modern ideas about the etiopathogenesis of allergic dermatoses, two solutions to this problem are possible. First, in the classification of dermatitis it is necessary to distinguish: simple (artificial) contact dermatitis, caused by unconditioned (obligate) irritants, and allergic dermatitis, caused by conditioned (facultative) irritants (allergens). In turn, allergic dermatitis is divided into contact allergic dermatitis, which occurs from direct contact of the skin with the allergen, and toxicoderma, which occurs when the allergen penetrates the bloodstream (through the gastrointestinal tract, respiratory tract and parenterally). With this division of dermatitis, eczema is presented as a chronic, recurrent allergic disease, arising as a result of polyvalent sensitization of the body and manifested by true polymorphic rashes (spots, papules, vesicles, pustules) with a tendency to vesiculation and weeping, with the subsequent development of false polymorphism (evolution of primary elements with the appearance crusts, scales, pigmentation, lichenification).

With this approach, eczema can only be considered a disease that has a chronic course with frequent relapses and short remissions. When a characteristic pathological process occurs for the first time, it is impossible to predict how the disease will develop - whether it will become protracted, recurrent, or will never happen again. Consequently, the first episode of the disease and extremely rare relapses over a long period of time should be considered as manifestations of allergic dermatitis. A prolonged course of newly diagnosed dermatitis cannot be diagnosed as eczema. There are cases when allergic dermatitis lasts 3-4 months and never recurs.

Secondly, if allergic dermatitis is excluded from the classification of dermatitis, leaving only simple contact dermatitis, then the manifestations of allergic dermatitis (contact and toxicoderma) should be regarded as acute eczema. In this case, eczema should be interpreted as an allergic disease with mono- or polyvalent sensitization, manifested by true polymorphic rashes (spots, papules, vesicles, pustules) with a tendency to vesiculation and weeping, with the subsequent development of false polymorphism (evolution of primary elements with the appearance of crusts, scales , pigmentation, lichenification), characterized by acute and chronic course.

In the case of monovalent sensitization, eczema will be regarded as acute, since it (according to modern concepts) is nothing more than allergic dermatitis, which has a similar clinical picture. When polyvalent sensitization occurs, when any of the allergens (or the combined effects of allergens) can cause or aggravate the allergic process, it becomes protracted, recurrent in nature, and in this case we will talk about chronic eczema.

We deliberately included in the wording such features of eczema as vesiculation and weeping. This must be taken into account to differentiate eczema from neurodermatitis, because with eczema at the time of examination there may not be vesiculation and weeping, although anamnesis most often reveals this.

In conclusion, it should be noted once again that, despite the centuries-old history of dermatology, a clear understanding of dermatitis and eczema has not been formed and, given the relevance of this problem, we invite dermatologists to discuss it in order to develop a consensus on standardizing the concepts and criteria for assessing the quality of medical care for allergic dermatoses.

How to recognize atopic dermatitis?

Tests often used in diagnosis are skin tests and atopic patch tests, but a negative test does not always mean that the disease is not present, it may only mean that the allergen has not yet been detected.

The laboratory also performs total serum IgE determinations, which determine the patient's allergies. Since atopic dermatitis is an allergic disease, we cannot completely cure it, we only treat it symptomatically. In some cases, it is possible to desensitize the patient.

How to live with dermatitis

Atopic dermatitis in adults can become chronic, and then you will have to fight it all your life. There is no cure for eczema, but the good news is that the disease can be controlled by keeping symptoms to a minimum. To do this you need 18:

• know and exclude contacts with triggers that provoke inflammation,
• take good care of your skin,
• use medications prescribed by a specialist.

It is very important to individually select the type and form of the drug so that the therapy is effective and comfortable for the patient. This also applies to topical steroids. In addition, you need to constantly monitor the development of the disease and be under the supervision of a specialist. Long-term remission may be a reason to gradually discontinue medications or switch to small doses of the drug. If symptoms increase, the specialist will help adjust the treatment plan by selecting a new therapy.

Unfortunately, sometimes eczema is unpredictable. It can flare up suddenly, and sometimes it can be difficult to understand why it has returned. The cause of its manifestation may be stress, anxiety, climate change or the quality of tap water. Living with eczema, you always need to be on guard. But even if the disease makes itself felt at the most inopportune moment, you should not perceive it as a disaster. Since our emotional state is closely related to the manifestations of eczema, we can overcome the disease only by accepting our skin as it is. There is no need to hide dermatitis, it needs to be treated, and then the skin will definitely reciprocate the love shown.

How to prevent and treat recurrent inflammation in AD?

Treatment of AD is complex and requires constant monitoring of skin condition. This is especially important for children, who most often cannot determine which foods they are allergic to and in what situations. Patients must minimize exposure to allergens, which is not easy due to the multiplicity of allergens and their prevalence.

Symptoms of atopic dermatitis increase in response to stress, so to prevent relapses, it is recommended to avoid stressful situations, especially when it is chronic.

During an exacerbation of symptoms, it is necessary to consult a dermatologist who will select appropriate antihistamines, which also have antipruritic properties, and other drugs that inhibit the development of allergies - for topical or general use (for example, immunosuppressants).

Treatment of recurrent inflammation in AD

It is worth taking care to exclude from the diet foods that make patients feel unwell and give a rash. Avoiding allergens in powders and mouthwashes that are highly irritating to already affected skin is also key.

Avoid clothing made from wool and other “caustic” materials. The quality of the bed linen on which the patient sleeps is important. It should also be soft and non-irritating. Hygienic and cosmetic procedures also affect the condition of the skin in AD. Avoid exfoliating cleansers and soaps and moisturize and lightly lubricate your skin regularly.

How to escape from dermatitis?

Atopic dermatitis cannot be completely cured, but it is possible to reduce the severity of its symptoms or even achieve stable remission. The three steps to healthy skin are cleansing, moisturizing and drug therapy. Patients with eczema may be prescribed:

• local steroid drugs,
• steroid injections,
• immunosuppressants, which suppress the body's immune response,
• antihistamines,
• antibiotics in case of infections,
• phototherapy - treatment with ultraviolet light.

At the same time, topical steroids - ointments, creams and gels - remain the most widely used remedy against eczema and the “gold standard” of treatment.8

In 2022, 55% of eczema patients were actively using topical corticosteroids.9

What is the secret of their popularity? The thing is that glucocorticosteroids in such creams act directly on the cells of the epidermis, providing an anti-inflammatory effect on damaged areas of the skin. Being synthetic analogues of human steroid hormones, they attach to cellular receptors and trigger a cascade of chemical transformations in cells. Thanks to corticosteroids, the production of inflammatory mediators responsible for pain and swelling in the tissue is reduced. In addition, corticosteroids (fluticasone propionate, betamethasone dipropionate, clobetasol propionate, etc.) help to narrow capillaries and reduce allergic and immune reactions, which make atopic skin so sensitive.10

The great advantage of the latest generation of topical steroids, such as fluticasone propionate11, is their safety profile. They tend to clear faster and have less impact on the body's immune and hormonal systems compared to first-generation corticosteroids.

Important! Many topical steroids are available without a prescription, but consultation with a specialist is required before using them. Drugs in this group have contraindications, and their long-term, uncontrolled use can lead to thinning of the skin, the appearance of acne, addiction and other side effects.12

Who needs topical corticosteroids

Topical corticosteroids are the second step in the treatment of eczema, which is resorted to if the disease worsens even after following all the usual recommendations of specialists. Sometimes patients regularly moisturize their skin, take warm baths and avoid any contact with irritants, but still suffer from itching, redness and pain.

In this case, topical steroids are an excellent way to relieve inflammation and overcome symptoms where other means are powerless. A properly selected cream can quickly alleviate the condition, playing the role of an “ambulance”, allowing the skin to recover and speed up healing.

Important! Before using a cream containing glucocorticosteroids, be sure to read the instructions. Schemes for using different creams may differ. As a rule, the cream is recommended to be used after taking a bath, applied to the affected areas in the direction of hair growth. The thighs and crease areas may need a little more cream than other areas.13 You can apply a moisturizer on top of the steroid cream.

What should a new generation cream be like?

When choosing a cream based on corticosteroids, you should pay attention to its composition. The latest generation of corticosteroids, such as fluticasone propionate,11 are potent and have a low risk of cutaneous and systemic side effects. In addition, the cream should have caring properties (Fig. 3) and be comfortable: absorb quickly, not leave a film, and not have a strong odor. If the disease causes severe dry skin, it is better to choose an ointment, and in case of weeping rashes, light cream-like textures are suitable.

Figure 3. What qualities should a cream based on glucocorticosteroids have? Illustration: MedPortal

One example of a modern remedy against dermatitis is the new product FeniVate - a drug of the latest generation with a pronounced anti-inflammatory effect in the form of ointment and cream.14-16

FeniVate is created using a special micronization technology, which promotes better penetration of the active substance into the epidermis. The drug works at the cellular level, has a targeted effect on the source of inflammation and helps not only to cope with the symptoms of allergic dermatitis, but also to suppress the inflammatory reaction on the skin.14

Why is it so important to overcome steroid phobia?

Topical steroids help quickly relieve eczema symptoms and control the progression of the disease. However, many patients refuse to resort to them for fear of encountering side effects from taking hormonal drugs. Today, experts call steroid phobia one of the main reasons for the development of complications of atopic dermatitis: pustular skin lesions, inflammation of the eyelids and conjunctivitis.17

Don't let fear affect your quality of life. Local steroids have a moderate effect on systemic processes in the body.12 And to reduce the risk of unwanted side effects to a minimum, you should regularly visit a specialist and adjust therapy in a timely manner if it becomes ineffective or causes discomfort.

Atopy is not only a disease of the body

Atopic dermatitis is a disease that can have a negative impact on the patient's psyche. Children and adolescents diagnosed with AD are more likely to have problems being accepted in their community. It is difficult to explain to your peers where the red spots and scars come from after an exacerbation of the disease.

Fortunately, only about 30% of patients continue to have symptoms into adulthood. In the remaining 70%, the symptoms disappear completely or appear in a milder form, which the patient can control with the help of a good dermatologist.

Diagnosis of atopic dermatitis (AD): skin tests

When diagnosing atopic dermatitis, in addition to analyzing symptoms and laboratory tests, a series of skin tests, such as skin tests, atopic patch tests, or nutritional skin exposure tests, are performed to identify the substances responsible for an excessive allergic reaction.

The diagnosis is confirmed by immunological laboratory tests - determining the concentration of IgE antibodies - and a number of skin tests that can identify allergens responsible for an excessive allergic reaction.

Etiology and pathogenesis

The main role in the pathogenesis of atopic dermatitis is played by hereditary determinism, that is, heredity. It is a number of hereditary mutations in genes that lead to disruption of the skin barrier and defects of the immune system. The patient also has hypersensitivity to allergens, an increased number of inflammatory mediators and a number of pathogenic microorganisms such as Staphylococcus aureus and Malassezia furfur.

The pathological reaction of the body, which provokes atopic dermatitis, occurs as a result of the interaction of three factors:

• skin barrier dysfunction;
• disturbances in the functioning of the immune system;
• influence of environmental factors.

In addition to the factors described, skin barrier dysfunction can be affected by:

• Reduced levels of ceramides (lipids), which protect the skin from aggressive environmental influences.
• An increase in proteolytic enzymes - substances that are responsible for the speed of cell reaction to external stimuli.
• Exposure to proteases from house dust mites or Staphylococcus aureus.

Violation of the protective barrier leads to high skin permeability to allergens and toxins. As a result of their penetration into tissues, a pathological immune response occurs. It comes from Th2 (T helper cell type 2), a special type of cell that enhances the adaptive immune response. They activate B lymphocytes that produce immunoglobulin E (IgE), which results in an allergic reaction.

During an immune response, characteristic itching and rash appear on the skin. Constant scratching stimulates the production of anti-inflammatory cytokines, which in turn cause chronic inflammation. As a result, the epidermis intensively absorbs allergens, which provokes microbial colonization of the skin.

Skin testing (STP)

Skin prick tests test for a specific allergen. This test is based on the fact that IgE antibodies are present on the surface of immune system cells. The purpose of the test is to bring such cells into contact with the allergen.

A solution containing the allergen is applied to the patient's skin, and then it is pricked with a special lancet. Typically, this test tests several substances at the same time, such as dust, hair or pollen.

Skin tests

This test is no different from a test that determines an allergy to any substance. Therefore, the presence of a positive allergic reaction does not automatically mean atopic dermatitis. In addition to the allergic reaction, other symptoms such as dry and itchy skin should also appear. Additionally, a negative test result does not mean that the disease is not AD; it only means that this set of substances does not cause allergic reactions.

How does the immune system normally work?

The concept of atopic dermatitis reflects the immunological mechanism of pathology development. It is based on the body’s ability to produce an excess amount of antibodies in response to incoming allergens. Antibodies combine with the allergen, which provokes a more pronounced allergic reaction than should be normal.

Let's figure out how the immune system should work normally. It’s worth starting with the fact that the system is represented by several organs (thymus, lymph nodes) and immunocompetent cells. Their main task is to protect the body from foreign elements: viruses, bacteria, fungi and allergens. This is accomplished through the development of protective reactions that are provided by certain cells. That is, the immune system recognizes foreign elements, destroys them and forms immunological memory.

Two types of cells help to perform such functions - B-lymphocytes and T-lymphocytes (killers, suppressors and helpers). Each type of cell has its own role in the operation of the system. Thus, B lymphocytes recognize foreign elements and form memory cells. T-killers are necessary to destroy foreign elements, T-helpers are involved in strengthening the immune response in response to the penetration of pathogenic agents. Suppressor T cells regulate the strength of the immune response by controlling the number of helper and killer cells.

The key to proper functioning of the immune system is a certain ratio of immunocompetent cells. With any quantitative disturbances, the immune reaction becomes pronounced, which is what happens during atopic dermatitis.

To prevent repeated exposure to the pathogen, the immune system forms a memory. It is synthesized by certain antibodies, or immunoglobulins, that form on the surface of B lymphocytes. Antibodies are proteins that have high specificity for antigens. As a result of their connection with antigens, an immune response is triggered in the body.

Several types of antibodies may be present in the body - immunoglobulins A, M, G and E. Each of them has its own function. For example, immunoglobulins A are responsible for protecting the respiratory tract. Immunoglobulins M and G are components of humoral immunity and arise as a result of the penetration of bacteria and viruses. Also, immunoglobulins G appear some time after the disease and can remain in the body for up to several years.

Immunoglobulins E arise as a response to the penetration of allergens. They are the ones who trigger an allergic reaction, which is accompanied by the release of various biological substances (for example, histamine). Under the influence of these substances, a person develops characteristic allergy symptoms: redness, itching, swelling.

Normally, the body contains very little immunoglobulin E, since these cells quickly disintegrate. However, as a result of a genetic mutation, some people have very high levels of these immunoglobulins, which increases the risk of developing atopic dermatitis on the face and body.

When it first encounters a foreign element, the immune system synthesizes certain antibodies. They help protect the body from re-infection for a certain period of time. During an allergic reaction, the process occurs differently. Upon contact with an allergen, a sufficient amount of antibodies is produced, which will subsequently bind to the allergen. Upon repeated contact, an antigen-antibody complex appears. An allergen acts as an antigen. An antibody is a protein produced by the body.

The antigen-antibody complex triggers a whole chain of immunoallergic reactions. With a large amount of immunoglobulin E, a pronounced and prolonged allergy appears. Simultaneously with the allergic reaction, a number of biologically active substances are released. It is these substances that trigger pathological processes that lead to the appearance of typical allergy symptoms. If the amount of immunoglobulins remains high, then the allergic reaction does not disappear, which indicates the development of atopy.

Atopic patches (ATP)

Atopic patches are a type of epidermal patches in which specially prepared allergens are applied to the uninjured skin of the patient's back and sealed. They are used to detect delayed allergenic reactions that cannot be detected by skin prick tests.

Atopic patches are a very good addition to the diagnosis of AD with substances that the patient must eliminate from life in order to reduce the symptoms of the disease.

Atopic patches

Skin application with SAFT nutrition test

SAFT is a food allergy testing method primarily used for young children. The technique involves eating the food that is suspected of causing the child's allergy and monitoring symptoms.

If erythema, itching and swelling of the skin occurs during use, this indicates a positive result, that is, an allergy. Most often, this test is carried out on allergenic fruits, vegetables, milk, chicken eggs and nuts.

Diagnostic problems in diagnosing blood pressure

Atopic dermatitis poses diagnostic challenges because some of the symptoms of atopic dermatitis are common to other skin diseases. Atopy is sometimes confused with psoriasis, symptomatic scabies, or a mild rash. The Williams or Hanifin and Raike AD diagnostic criteria sets are useful in making a diagnosis.

It is also not always easy to identify the allergens responsible for the occurrence of unpleasant symptoms. A negative skin test does not always mean that the disease is absent, it can only indicate that the sensitizing allergen has not yet been detected. Meanwhile, it is the correct choice of substances that the patient should eliminate from life in order to reduce the symptoms of the disease that is the key to improving his well-being.

Determination of total concentration of IgE antibodies

The simplest test performed to diagnose AD is to determine the total concentration of IgE antibodies in the blood. This concentration is indicated in IU, and the standard is 100 IU/ml. In patients with atopy, the total concentration of IgE antibodies increases by 80%. There is often a relationship between IgE concentrations 10 times normal and the clinical condition of the patient's skin. The higher the antibody concentration, the worse and more severe the skin changes.

Therefore, patients with atopic dermatitis can be divided into two groups: those with elevated antibody levels and those with normal antibody levels (about 20% of patients).

• In the first case, we talk about extrinsic atopic dermatitis (extrinsic atopic dermatitis - EAD) because the symptoms are caused by allergens coming from the environment.
• Less commonly, we deal with intrinsic AD (intrinsic atopic dermatitis - IAD), where symptoms arise from non-immune causes, such as a skin defect or a nonspecific inflammatory response. This means that an IgE result within the normal range does not necessarily rule out atopic dermatitis.

How is atopic dermatitis diagnosed? Criteria for diagnosing blood pressure

When diagnosing atopic dermatitis, in addition to immunological laboratory blood tests, the key is to analyze the patient's skin condition and its symptoms in accordance with the criteria of Williams and colleagues or the criteria of Hanifin and Raika.

Atopic dermatitis (AD) is a chronic disease with a complex cause. Its appearance is influenced by immunological, genetic, non-immunological and environmental factors. Therefore, this is not just an allergic reaction. For this reason, the basis for correct diagnosis of AD is the overall picture of the disease, especially the appearance of the skin.

Atopic dermatitis is a disease that causes diagnostic problems - similar symptoms can occur with other types of dermatitis, such as seborrheic or sweat dermatitis, contact eczema, mycosis or psoriasis. The most common diagnosis of atopic dermatitis is the so-called Williams and colleagues criteria or Hanifin and Reike criteria.

Seborrheic dermatitis

Psoriasis

Causes of the disease

There is no single cause for the development of atopic dermatitis. The occurrence of the disease is facilitated by a whole complex of conditions: genetic characteristics and environmental factors. These include a violation of the protective function of the skin (it becomes more vulnerable to the effects of detergents or other irritating factors), characteristics of the immune system, climatic conditions (temperature, humidity, dust, tobacco smoke and other impurities in the external environment). Possible effects of the microbiome are being studied.

Williams criteria for diagnosing AD

According to the Williams criteria, to diagnose atopic dermatitis, it is necessary to establish whether itching has occurred within the last year and at least 3 of 4 symptoms:

• involvement of skin folds (elbow and knee), changes in the neck or around the eyes;
• coexistence of other atopic diseases, for example, bronchial asthma or hay fever (when diagnosing children under 4 years of age, atopic diseases in 1st degree relatives are taken into account);
• general dry skin throughout the year;
• visible inflammatory changes in the flexion areas of the limbs and on the cheeks/forehead and elongated parts of the limbs in children under 4 years of age or onset of the disease before the age of 2 years (not applicable if the child is under 4 years of age).