Skin tests for allergies. Allergy tests. When to get tested for allergies

Allergy tests for children are prescribed in cases where a child has a negative reaction from the body in the form of a rash or itching, but the reason for this is unknown. This type of analysis can be done either in the form of an immunological test, that is, by testing the blood, or by the skin method.

At the moment, allergy tests can be of 3 types:

Allergens are applied directly to the child's skin (direct tests). At the same time, the specialist makes scratches on the skin to introduce allergens into them. Next, they look at the skin reaction, and if any negative reactions appear, such as swelling, peeling or redness, a conclusion can be drawn as to the cause of the allergic reaction in the child. As a rule, such diagnostic methods are carried out under the constant supervision of specialists in a hospital, since it takes some time to obtain results.
Studies of a provocative nature, which include the use of nasal, inhalant or conjunctival agents. Allergy tests in children are taken when there are clinical manifestations of allergies and discrepancies in the results of skin type tests.
Tests of an indirect nature, when an irritating substance and a serum sensitive to this allergen are injected by subcutaneous injection. The reaction obtained during the research allows us to determine which allergens are dangerous for the child.

Advantages and disadvantages

As for such research as skin tests for allergies, their main advantage is that they are quite accurate in terms of obtaining results. Another advantage is their simplicity and accessibility. If we talk about the disadvantages of this method, then we should include, first of all, the possible risk of a negative reaction of children to the test, therefore this type of diagnosis is carried out exclusively in a medical institution. However, there are a number of negative aspects of this test. This is, firstly, the painfulness of the procedure, and secondly, the research time is quite long.

If you take a blood test, the advantages of this method include the following points:

The use of specific allergens allows you to obtain the most accurate data.
There is absolutely no contact with allergic elements.
A blood test can be taken at any time, even if the child is experiencing an exacerbation of an allergic reaction.
Regardless of the number of allergens, it is enough to donate blood just once.

As for the disadvantages of this research method, it is only its high cost.

Contraindications to allergy testing

Skin allergy tests have the following contraindications:

this method cannot be used if there is any damage to the skin;
when using antihistamines, since they lead to a decrease in the sensitivity of the skin;
with increased skin sensitivity to the allergen due to the high risk of a false result;
if the child has experienced anaphylactic reactions or has a predisposition to this;
You cannot do such tests if the child is under 3–5 years old;
with long-term treatment with corticosteroids;
if there are any acute infections.

This list should also include infants under one year of age, since they may have antibodies in their blood that were passed on from their mother.

At what time are allergy tests carried out, and what analysis should I choose?

If skin tests are performed, they should only be done during remission. After the exacerbation has ended, at least a month must pass to conduct a new study. Since it is impossible to predict how the body of a small child will behave, the study should be carried out only in a hospital under the constant supervision of specialists. But as for the analysis with blood sampling, it can be done at any time, however, with the exception of infants.

The main thing to remember is that skin testing for allergens in children should not be performed on young patients under at least 3 years of age.

According to most allergists, it is best to do such studies in children only after 5 years of age, except in cases where the body’s allergic reaction manifests itself in an acute form.

Laboratory blood test for allergens

Many people know what allergy tests are and how they take blood for analysis. It is worth noting that this research method is considered the safest, so it can be performed on both adults and infants. With its help, the body's reaction to all types of allergens is studied, while there is no direct contact with them, which makes this method even more attractive. During the procedure, IgE antibodies are detected in the patient’s blood, which react to the appearance of an allergen in the body. Depending on its concentration, decoding and final conclusions are made regarding the severity of the body’s reaction to the allergen.

Thus, you can check your reaction to 200 types of allergens.

Preparation for allergy tests involves not eating before the test, i.e. blood is donated on an empty stomach. In addition, there should be no physical or emotional stress on the body.

If a child is being tested, and the question arose about how to prepare for the test, then a day before donating blood, a diet should be prescribed that excludes fatty, sour, spicy, sweet and possible allergens.

Causes of an allergic reaction in an infant

When it comes to infants, parents are often interested in the question of how to determine what their baby is allergic to, if it is impossible to take allergy tests in this case. It all depends on the patience and attentiveness of mom and dad. It is necessary to carefully monitor the child’s diet and exclude potential allergens.

Depending on what the baby eats, methods for identifying allergens are as follows:

If the child is breastfed, the mother should monitor the diet and not eat foods with increased allergenicity. These include vegetables and fruits that are red and orange in color. In addition, you should not eat citrus fruits and chocolate. Honey is also on the list of allergens, so you should avoid it too.

If the baby eats formula, the cause of the allergy should be looked for in its composition. Perhaps the body gives a similar reaction to lactose. Although often the cause is too frequent changes in diet.
When complementary foods are introduced, and this usually happens at the age of 6 months, the baby may experience an allergic reaction to some foods, so it’s worth starting with hypoallergenic ones.
Due to the fact that the body of an infant is not yet formed, the amount of food taken is also important, since too much food can cause a negative reaction.

If the parents were unable to independently identify the allergen, the baby is prescribed laboratory tests by drawing blood.

Parents can easily identify the allergens to which their child has a negative reaction, just by carefully monitoring their baby.

However, even if it seems that the cause has been found, the assumption can only be confirmed through laboratory tests using allergy tests.

If we talk about infants, then in order for the baby not to have allergies, the mother must eat properly and well during pregnancy and breastfeeding. To do this, a woman must exclude foods with increased allergenic activity from her diet.

When a person has an allergic reaction, he is required to undergo a skin test. In a study such as allergy tests, their essence and application are aimed at identifying the sensitivity of a particular patient to various allergens. The preparations used for allergy tests are based on all kinds of materials with which a person constantly comes into contact. This is the hair of pets, their dander, pollen from plants and trees, and house dust.

In addition, all kinds of household and bacterial fungi are used.

As for how allergy tests are done, the allergen is injected under the skin or onto a scratch made in advance using a syringe. If a person has increased sensitivity to it, a red spot or swelling appears at the site where the product was injected (after 15 minutes).

In what cases are allergy tests prescribed?

Among the indications for research, the list of which includes a skin allergy test with anthraxin, it is worth highlighting the following diseases:

allergic dermatitis, which is expressed by severe itching and rashes on the skin;
asthma with shortness of breath, difficulty breathing and suffocation;
food allergies that cause itching and rashes;
conjunctivitis and allergic rhinitis with runny nose, itching, lacrimation and redness of the eyes;
chronic or seasonal hay fever, manifested by itching in the nose, congestion, runny nose and constant sneezing;
allergies to medications with itching and rash.

As for the age at which allergy tests are done, the child must be at least 5 years old. In addition, by the time of the study he should not be sick with anything. Otherwise, it is impossible to predict the body’s reaction and the result of the analysis.

Side effects from the study

In a person undergoing allergy tests, consequences such as hypersensitivity are possible, which usually occurs after 6 hours, and it can last throughout the day. It manifests itself in the form of poor healing of the area where the study was carried out and the emergence of a risk of sensitization.

In severe cases, allergy tests can lead not just to discomfort, but to death.

However, such cases are very rare, since the study is carried out in a medical institution under the supervision of specialists.

proallergiu.ru

Allergy tests - indications for testing

Allergic diseases are practically the most common diseases in the world. According to statistics, every fifth inhabitant of the planet suffers from them, and every year the number of allergic reactions increases - this is due to many factors: stress, poor nutrition, poor environmental conditions, etc. Thanks to this, the body begins to show sensitivity to certain substances, which are called allergens.

It is almost impossible to find out on your own what the allergic reaction occurred to, so you need to seek qualified medical help from an allergist.

This testing method is indicated if you have:

allergic asthma: shortness of breath, chest pain, cough, difficulty breathing
allergic conjunctivitis and rhinitis: itching, redness and swelling of the eyelids, frequent sneezing, watery nasal discharge, itching in the nose and nasal congestion
allergic dermatitis: various skin rashes
manifestations of food, drug and insect (insect venom) allergies
allergic reactions that occur to flowering plants

Allergy tests - essence and technique

There are four types of skin tests:

prick skin tests
prick test
intradermal tests
patch tests (patch test)

Testing is carried out using concentrated allergens, which are introduced into the human body in various ways. Let's take a closer look at how an allergy test is done.

Scarification skin test: the doctor applies small drops of the allergen to the skin of the patient’s forearm, then makes minor scratches with a lancet, thanks to which the allergen penetrates the skin. When carrying out this test, the body’s reaction can be assessed after 10-15 minutes.

Carrying out a scarification test

Scarification tests are done for:

detection of airborne allergens: pollen, mold, dust, fluff and wool, etc.
identifying probable food allergens: milk and dairy products, fish and seafood, cereals, fruits, vegetables, etc.
determining sensitivity to drugs and insect poisons

Prick test. It differs from the scarification test by the method of violating the integrity of the skin. When conducting a skin prick test, a lancet is used to make a 1 mm deep puncture of the skin, rather than a scratch.

Carrying out a prick test

Intradermal test: the doctor introduces a small dose of the allergen under the patient’s skin. This test is more sensitive than the scarification test and is prescribed if the substance did not cause a reaction during the scarification test, but is still considered as a possible cause of allergies in humans.

Intradermal test

Application test (patch test). This method involves the use of patches treated with allergens, which are attached to the area between the shoulder blades.

Conducting a patch test

During the test period, it is forbidden to carry out water procedures and play sports, as this can lead to the patches coming off. The result is assessed a day later (in some cases or more) after applying the patches.

This test is used to detect skin allergies (various dermatitis) to latex, drugs, hair dye, metals, food, etc.

Allergy tests for children can only be done when they reach the age of five, since the children's immune system has not yet strengthened until this age, and this can lead to serious consequences in the form of acute allergic reactions. In addition, the procedure itself is quite painful for the child. In this regard, doctors recommend replacing skin tests for allergens with a blood test in children.

Where can I get allergy tests?

Where to test for allergies - this question interests many people who want to determine the cause of the disease.

Allergy tests can be done in medical centers, skin clinics and clinics that have an allergist on staff.

The tests are carried out under the supervision of a doctor, since he has available medications that may be required in the event of acute allergic reactions or anaphylactic shock that pose a threat to the patient’s life.

Skin allergy tests - preparation for testing

Before doing allergy tests, to assess the general condition of the body, doctors recommend taking the following tests: clinical and biochemical blood tests, urinalysis, coprogram.

Also, 10 days before the test, you should stop taking various medications that may show a false negative result of allergy tests (antihistamines, antidepressants, etc.)

Decoding the research results

Interpretation of skin test results:

The result is negative: no changes occurred in the area of skin in contact with the allergen.

The result is positive: skin swelling (blister) of 3 mm or more has formed. The larger the size of the resulting blister, the higher the degree of sensitivity to the injected allergen - treatment is required.

Positive reaction to allergens

Contraindications

Contraindications to the procedure are:

age under 5 years and over 60 years
ARVI, sore throat and other infectious diseases
pregnancy, lactation
allergic reactions that occurred during the current month

In case of allergies to plant pollen, an allergy test is carried out in the autumn-winter period, when the flowering of plants has ended and the allergic background has become lower.

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Skin tests

Allergy tests on the skin are a method for diagnosing the specific sensitivity of the body. It is carried out at the first stage of pathology assessment. The indication for skin allergy tests is information from the anamnesis (questionnaires, conversations with parents), indicating the role of a causal factor of a particular allergen or group.

Features of the method

The diagnostic principle is based on the interaction of the causative allergen with skin cells. If there is sensitization, a local reaction develops. The allergist notes its intensity. When choosing allergens administered to children, information obtained from a survey of parents is taken into account.

This type of diagnostics is economical and quite sensitive. However, to avoid erroneous results, it is important to perform the placement technique correctly. The result of the test for allergic diseases is visible almost immediately. The method is safe and has no age restrictions.

How are allergy tests done?

Diagnostics are carried out using ready-made water-salt extracts of various allergens: epidermal, pollen, food, dust.

When testing using the scarification method, drops of allergens are applied to the child's small scratches on the back of the forearm. The drops are on the skin for 10 minutes. Then they are wiped, wait 10 minutes and see if redness and a blister appear. The conclusion about a positive result is made based on the coincidence of stories received from parents with skin reactions + + for children under 3 years of age and +++ for children after 3 years of age.

The decoding of samples using the scarification method is as follows:

Types of skin tests

If the results of prick tests are questionable, intradermal tests are performed. When they are carried out, there is a risk of developing a systemic reaction. Therefore, the allergen solution is diluted 100 times or more.

With the prick test technique, allergens are injected into the skin using special disposable lancets. Most often, testing is performed on the palmar surface of the forearm or on the back.

To diagnose contact allergic dermatitis and photoallergic reactions, patch tests (path-tests) are performed. Medicines and chemicals are taken as allergens. The solution is used in concentrations that do not cause skin irritation in healthy people.

To do patch tests, you will need to visit the doctor 3-4 times. During the first visit, the allergen is applied to the skin. After two days, the flaps are removed and after 15-20 minutes the doctor looks at the local reaction. The test conclusion is made upon examination after 72 hours.

Rules for skin testing

Skin allergy tests are carried out only in a medical institution where there is medical equipment, qualified personnel and medications in case of the possibility of developing anaphylactic shock. However, such a diagnostic outcome is very rare.

For children under 3 years of age, the examination is carried out incompletely: no more than 5 tests with non-infectious allergens can be performed at a time. No more than 10 tests are performed in older children.

Preparation for allergy tests excludes taking antihistamines 2-3 days before testing, mast cell stabilizers (ketotifen) 14 days before testing. It is not advisable to carry out the test while taking antibiotics.

If fungal sensitization is detected, it is necessary to exclude from the diet 2 days before the test foods containing microscopic fungi: moldy cheeses, kefir, cottage cheese. These products should not be consumed on the day of diagnosis or the next day, as local reactions may be activated within 24 hours.

Skin testing is rarely performed to diagnose drug allergies in children, since sensitization is usually caused not by the drug itself, but by its breakdown products. They are difficult to define.

Skin testing for allergens in children has contraindications. Diagnosis is not carried out during the period of exacerbation of the disease and immediately after an acute allergic reaction, when a secondary infection occurs, if the child has experienced anaphylactic shock or suffers from nervous disorders.

Allergy tests in children have a high reliability (95%) in case of a negative result. The introduction of an allergen cutaneously in the absence of a local reaction excludes the presence of sensitization to it. If the reaction is positive, in some cases the test gives a false result. They may be caused by decreased skin reactivity in young children (under 5 years), improper storage of allergens, or a violation of the technique for performing allergy tests for children.

Provocative tests

The principle of provocative tests is to evaluate the patient's reactions when introducing a gradually increasing amount of causative allergens. This is the most accurate diagnostic method, but also dangerous. It is carried out under strict indications during the period of disappearance of symptoms of the disease.

Depending on the method of allergen administration, provocative tests can be nasal, conjunctival, or inhalation. For children with food allergies, the intended product is given by mouth.

The disadvantages of provocative tests are as follows:

You can test only one allergen at a time;
the results of the study are difficult to quantify, especially in allergic rhinitis or conjunctivitis;
the method is associated with a high risk of developing severe allergic reactions.

Tests are contraindicated if there is a history of immediate development of urticaria, angioedema, asthma attacks or anaphylactic shock upon contact with this allergen.

Laboratory diagnostic methods

The examination includes only those studies that help determine the spectrum of sensitivity and changes in the organs and systems involved in the pathological process.

Laboratory diagnostic methods are used quite widely, as they have a number of advantages:

carried out in early childhood;
can be prescribed during exacerbation of the disease and when taking antiallergic drugs;
safe;
can be carried out in cases where the patient is at a great distance from the allergist and only the patient’s serum can be delivered.

General blood analysis

The child will need to donate blood to determine the number of eosinophils. Normally, the decoding of the number of eosinophils is as follows:

in newborns – 20-50 µl –1,
in children from 1 year to 3 years – 50-700 µl –1,
in adults – 0-450 µl –1.

A slight increase in the number of eosinophils to 5-15% is not pathological for atopic diseases, but suggests this diagnosis.

An increase in eosinophils in the blood by 15-40% of the total number of leukocytes may be a sign of an allergic disease.

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Allergic conditions and diseases in children are quite common. With this pathology, a number of diagnostic tests are used to clarify the diagnosis and prescribe the necessary treatment.

Allergy tests

Allergy skin testing is a traditional and reliable method for diagnosing allergies, a method for identifying the specific sensitivity of the body. Skin allergy tests usually include prick tests (prick test), prick tests (scratch test), and intradermal tests with different sets of allergens.

Indications for the purpose of analysis:

Diagnosis of allergic diseases (bronchial asthma, hay fever, atopic dermatitis, eczema, food allergies, drug allergies, respiratory allergies (rhinitis - runny nose, sinusitis - inflammation of the paranasal sinuses, laryngitis - inflammation of the larynx, tracheitis - inflammation of the trachea, bronchitis - inflammation of the bronchi, pneumonia - pneumonia caused by allergies) in the following cases

Contraindications include:

Exacerbation of a current allergic disease or other chronic disease;
Acute infectious process (ARVI, tonsillitis, etc.);
The patient's serious condition;
Long-term therapy with hormonal drugs (corticosteroids).

Before allergy testing, a general clinical examination is carried out: a general blood test, a biochemical blood test, a general urinalysis, and an examination by a pediatrician.

The test is carried out in order to determine which allergens may be important in the development of symptoms of the disease. The standard kit for skin testing includes allergens from plant pollen, house dust, wool, fluff, animal epidermis (skin), food products, etc. Skin tests are usually placed on the inner surface of the forearms, 3 cm from the wrist, in the presence of allergic diseases skin, tests are placed on areas not affected by damage, for example, on the back.

Children can only spend after 5 years of age .

This is due to the fact that children under 3-5 years of age have not yet developed immunity, which can lead to complications (from exacerbation of allergic reactions to exacerbation of chronic diseases). In addition, the procedure is quite painful. Therefore, at an early age, skin tests are replaced by a blood test to determine specific immunoglobulins for various types of allergens.

In children, given the possibility of severe complications, up to anaphylactic shock (a severe allergic reaction accompanied by disruption of vital functions of the body), as well as the difficulty of assessing the results, skin tests can only be carried out in special allergological institutions under the supervision of an allergist.

Carrying out analysis:

A drop of a diagnostic allergen is applied to the site of an injection or scratch made with a sterile disposable scarifier or certain allergens are injected intradermally. After some time, slight swelling and redness of the skin may develop, which suggests an allergy to the given allergen. The results are assessed in bright light after 24 hours and 48 hours. The test is considered positive if the diameter of the papule (from the Latin papula - pimple, an element of a skin rash - a small dense nodule slightly raised above the skin) is more than 2 mm. In one study, it is possible to evaluate 15-20 samples. This is a fairly accurate and time-tested method for diagnosing allergies.

A few days before skin testing, you must stop taking antiallergic medications, otherwise the results will be unreliable. Based on the results of skin tests, specific immunotherapy can be carried out. Once the cause of the allergy is determined, it must be eliminated. If you are allergic to dandelions, you should avoid contact with this type of plant. And also during the period of remission of allergies (beyond its obvious manifestations), specific treatment is selected under the supervision of an allergist. There are several treatment options. The main medications to combat allergies are antihistamines and allergy vaccination. But they do not lead to a 100% recovery. Allergy vaccination is a long process. It can take 1–3 years. When an allergen is introduced, the body becomes accustomed to it and begins to produce protective substances. The first 38–40 injections are given at intervals every other day, then a little less frequently, and when the maintenance dose is reached, injections are given once a month until the result is achieved. Antiallergic drugs are taken during exacerbation of the disease

Diagnosis of allergies using blood tests is a modern trend in allergology.

Determination of IgE in blood

IgE general – antibodies responsible for the development of allergic reactions).

It determines the concentration of IgE (immunoglobulin E) in the blood serum taken from the patient from a vein. Immunoglobulin E (IgE) is a class of immunoglobulins that is normally found in small quantities in blood serum and secretions. Typically, IgE concentration is expressed in IU/ml or kU/l (kU – kilounit).

IgE is involved in allergic reactions of type I (immediate) - for the immediate type, the period between the moment of contact with the allergen and the appearance of the first signs of an allergic reaction lasts from a quarter of an hour to several hours. In addition, IgE takes part in protective anthelminthic immunity (the immunity provided by the liver provides protection against helminthic invasion), which is due to the existence of cross-linking between IgE and the helminth antigen.

Over 200 allergens are used for the test. Its peculiarity is that the patient does not need to come into direct contact with the allergen, and the risk caused by this is eliminated. They have virtually no contraindications and are recommended for any form of allergy.

To diagnose allergies using blood tests, it is important to determine the presence of specific antibodies that react with allergens. Receptors for these antibodies are found on different cells of our body... The release of these substances upon contact with antibodies leads to the development of allergic reactions, which underlie allergic rhinitis, bronchial asthma, and some types of skin rashes.

3 days before taking blood, it is necessary to avoid physical and emotional stress.

Reference (normal) IgE values:

IgE level, U/ml

5 days -12 months

12 months – 6 years

10 – 16 years old

children over 16 years old and adults

An increase in IgE levels may indicate the presence of allergic diseases and some other pathological conditions.

Determination of specific IgG

The analysis determines IgG to the 90 most common food allergens

List of allergens: avocado, cow's milk, pineapple, carrots, orange, melon, quantalupe, peanuts, soft cheese, eggplant, oats, banana, cucumber, lamb, olives, beta-lactoglobulin, kola nut, grapes, halibut, gluten, black pepper , beef, chili pepper, blueberry, peach, grapefruit, parsley, walnut, wheat, buckwheat, millet, champignon mushrooms, spotted beans, pear, baker's yeast, rye, brewer's yeast, sardines, green peas, beets, green bell peppers – p.Capcsicum, pork, strawberries, celery, turkey, sunflower seed, yogurt, plum, casein, soybeans, squid, green beans, flounder, feta cheese, broccoli, cheddar cheese, cabbage, tomatoes, potatoes, cod, coffee, cane sugar, crab, tuna, shrimp, pumpkin, rabbit, oysters, corn, trout, sesame, hake, tobacco, cauliflower, chicken, whole grain barley, lemon, black tea, salmon, garlic, onion, Swiss cheese, butter, chocolate, honey, apple, almonds, egg white, goat milk, egg yolk.

Indications for the purpose of the study

In a complex of studies in complex cases of diagnosing food allergies and food intolerances.

Material for research: blood serum.

Units of measurement: The study is semi-quantitative. The result is given in crosses.

Interpretation of results:

deny. negative (< 50 Ед/л);
+ weak sensitivity (50-100 U/l);
++ moderate sensitivity (100-200 U/l);
+++high sensitivity (>200 U/l).

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In what cases is it necessary to do allergy tests?

In the presence of bronchial asthma, accompanied by heavy breathing, oxygen deprivation, shortness of breath.
In the presence of chronic hay fever, as well as seasonal, which manifests itself in the form of a runny nose, continuous sneezing, and constant nasal congestion.
For allergies to food and medications.
In the presence of allergic rhinitis, conjunctivitis.
For allergic dermatitis.

What types of allergy tests are there?

There are 3 main ways to conduct allergy tests:

Skin test or patch test.
Scarification test.
Prick test.

Solutions of various herbs, food, medicines, animal skin particles, insect venom, wool particles, chemicals and household preparations are used as allergens.

How are allergy tests done?

So how are allergy tests done? Carrying out application tests involves applying a gauze swab soaked in an allergen solution to the area of skin affected by the allergy.

During the scratch test, a few drops of the allergen are applied to an area of skin from the hand to the shoulder treated with alcohol. Then small scratches are made in this place with a scarifier for one-time use.

When conducting a prick test, a few drops of the allergen are also applied to the treated skin of the forearm and small punctures are made in this place with sterile needles 1 millimeter deep.

Another type of test is provocative, which are divided into conjunctival, nasal and inhalation. During a conjunctival test, the allergen is injected into the eye. If tears and itching of the eyelids appear, the result for the test allergen is positive. In a nasal test, the allergen is injected into the nose. An indicator of a reaction to an allergen is congestion or swelling of the nasal mucosa, continuous sneezing and itching. Using an inhalation test, you can determine the occurrence of bronchial asthma.

During one visit, no more than 15 samples are placed.

What can be the results after an allergy test?

The research results will not tell you right away. They can be ready either after 20 minutes (if it is, for example, a pollen allergy) or after 1-2 days (it all depends on the type of allergen) and contain the following answers: negative, weakly positive, positive and doubtful.

Redness and swelling greater than 2 millimeters in the area where the allergen solution was applied is the result of the fact that you are allergic to this particular substance.

How should you prepare for allergy testing?

To obtain more accurate results, you must stop taking anti-allergenic medications one day before the test. It is also advisable to conduct a general clinical examination: take blood and urine tests. It is best to do allergy tests in winter or autumn, because... In spring and summer, the number of allergens increases.

Where are allergy tests done, and who controls this procedure?

Many people do not know where allergy tests are done. However, you should know that allergy tests must be carried out and monitored by an allergist in the treatment room located in the allergy department.

How to diagnose and identify allergies if there are contraindications for testing?

If for some reason all types of tests are contraindicated for you, you can diagnose an allergy by taking a blood test from a vein.

Are there any contraindications for an allergy test?

The following contraindications may prevent an allergy test:

existing allergy at the time of the study in the acute stage.
acute respiratory infections.
any other existing chronic disease that is currently in the acute stage.
taking hormonal medications for a long period.
pregnancy.
currently taking antihistamines.
age after 60 years.

Is it possible to carry out allergy tests in children?

Allergy tests in children are usually carried out in the same way as in adults, but with an age limit of up to 3 years. If a child’s allergy occurs passively, without exacerbations, then tests are not recommended until age 5, because A growing child's body can cope with an allergic reaction on its own.

What could be the consequences of an allergy test?

The consequences of an allergy test are very rare and are manifested by a pronounced allergic reaction, sometimes leading to anaphylactic shock. Therefore, all allergy tests should be carried out in specialized medical institutions and only under the supervision of an allergist, who, if necessary, can provide professional assistance.

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Skin testing for allergies is a type of diagnosis aimed at identification of allergens, causing protective reactions in the form of allergies from the body.

This is necessary to prescribe the correct treatment, as well as to inform the patient about what foods, medications, chemicals and even animals he should avoid so that allergies do not manifest themselves.

Indications and contraindications - when to take?

Skin tests to identify allergens It is recommended to take it in the following cases:

the appearance of symptoms of allergic dermatitis, conjunctivitis,;
a tendency to allergic reactions in general (the subject often sneezes for no reason, his face and skin on his body turn red, and unexplained rashes appear on the skin);
manifestation of signs of allergies when taking certain medications and eating any dishes and products;
routine test for antibiotics and anesthesia before surgery or treatment;
seasonal allergies (hay fever or);
unclear origin of severe bronchial asthma.

But this procedure also has contraindications:

the subject is less than three and more than 60 years old;
the period of exacerbation of allergies and another three weeks after the allergy goes into remission;
acute reactions to allergen samples used in testing;
undergoing treatment with the use of sedatives and a week after completion of treatment;
diabetes;
AIDS;
oncological diseases;
any infectious and inflammatory diseases in acute form;
period of pregnancy and lactation;
menstrual period;
in the anamnesis;
treatment with hormonal drugs (tests can be performed no earlier than two weeks after the end of such therapy).

Provocative tests are not performed for colds of any origin: in such cases the result may be false, since the body’s defense mechanisms are aimed at its restoration, and some of the processes may be similar to those observed with allergies.

Skin testing may not always guarantee accurate results, so a blood test should also be performed to identify specific allergens as accurately as possible.

Types of samples

Skin tests to detect allergens are three types:

Since in all cases a small amount of allergens is used, other than local allergic reactions, no serious consequences develop.

But none of the methods guarantees that an allergy occurs to a specific allergen, so an additional blood test is required to confirm the results.

How much are?

The cost of skin testing varies widely depending on the types of allergens and their quantity, the method of testing and the medical facility where the procedure is performed.

Thus, a test for one allergen in a public clinic can cost about a hundred rubles, the same procedure in a private medical center can cost 8-10 times more, and a full examination involving several dozen allergens can reach up to 20-30 thousand rubles.

Such tests can be done in public or private clinics, skin clinics, individual laboratories and immunological centers.

How to prepare?

No special preparation is required for such procedures.

For two weeks Before testing, it is necessary to complete treatment with antibiotics, antihistamines, hormonal and sedative drugs.

During the week Before testing, foods that may be potential allergens (dairy products, fruits and vegetables, spices) should be excluded from the diet. In fact, during this week you should eat only neutral foods, but you do not need to exclude meat.

In 3-4 days Before the procedure, you should not drink alcohol, and you should refrain from smoking the day before.

How are they made?

Each type of allergy test has its own technique. Scarification test is performed in the following sequence:

The skin in the areas where the test will be performed is treated with alcohol for disinfection. In children, scratches are usually made on the back below the neck; in adults, this is on the forearm area.
Several scratches are applied at a distance of at least 4 centimeters from each other.
A solution containing allergens is placed into each incision using a lancet.

If the skin condition does not change within 15 minutes, the result is an allergen. considered negative. If during this time the skin swells, turns red and begins to itch, a reaction to the introduced allergen is registered.

Prick test is performed in exactly the same way, with the exception that no incisions are made, and allergen solutions are administered by injection.

At applications the skin is not damaged at all: external irritations and changes in the condition of the skin that may occur upon contact with a patch treated with an allergen solution are recorded. With any of these allergy tests, no more than 20 different allergens can be used simultaneously.

Allergy tests for antibiotics and anesthetics - algorithm of actions

This procedure is necessary to identify possible intolerance to certain antibiotics(eg penicillin).

If such drugs are prescribed in tablet form, then the easiest way to determine allergies is to place a quarter of such a tablet under the tongue. Next, the allergist assesses the condition of the mucous membrane after 20, 60, 120, 240 and 360 minutes. With allergies, swellings form under the tongue in the form of nodules with a diameter of more than 1 centimeter.

Alternative option - skin tests for antibiotic tolerance:

The saline solution is mixed with an antibiotic and injected into the forearm in a volume of 1 milliliter. The condition of the skin is assessed at the same time intervals as the sublingual test. If you are allergic to the drug, the injection area will swell and turn red.
The same solution is rubbed into the scratch on the forearm. Allergic reactions in the form of itching and redness will appear after half an hour.
A special patch is soaked in the solution and glued to the forearm. The result is visible after 20-30 minutes.

Allergy tests for anesthetics (lidocaine, novocaine) are performed using the same methods, but there are additional methods. One of them - blood analysis which will give the most accurate and objective result.

But sometimes, for various reasons, this test can give false results or show the absence of an allergy, even if there is one. In such cases, you can do a provocation test, which involves sequential injections with an antibiotic at certain time intervals.

Tsuverkalov's test

Allergy test according to Tsuverkalov is used not for allergy detection, and to confirm the diagnosis of “dysentery”, but at the same time a substance is introduced into the body that causes allergic reactions when administered with a hydrolyzate of dysentery bacteria (“Tsuverkalov’s dysenterin”).

This substance in an amount of 1 milliliter is injected into the forearm. The injection site is examined exactly 24 hours later. If a red swelling of 1 centimeter or more in area forms at the injection site, this is regarded as a positive result and dysentery is confirmed.

Carrying out skin allergy tests is a mandatory procedure that helps to identify an allergen or a group of them and prescribe appropriate treatment.

In some cases, such therapy may consist of taking general antihistamines, but in severe cases or with allergies to a specific substance, it is important not only to take medications, but also to limit contact with the allergen, otherwise treatment will be useless. For this, it is necessary to determine the causative agent of allergic reactions.

Video on the topic

Elena Malysheva will talk about three types of skin tests in her program:

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The term “allergy tests” or “allergy tests” refers to 4 types of tests:

skin tests,
blood test to determine the total level of immunoglobulin E,
blood test to determine specific antibodies,
provocative tests.

To make an accurate diagnosis, the results of one or two of the listed tests are required. The examination begins with skin testing. If there are contraindications, they resort to a safer diagnostic method - a blood test for antibodies. A provocative test for allergens is used only in extreme cases: if discrepancies arise between the results of studies already conducted and the patient’s medical history (for example, a survey shows that the patient is allergic to birch pollen, but skin tests do not confirm this).

Allergies to different substances most often present with the same symptoms. It is difficult to determine the cause of an allergy without using special skin tests, more commonly called allergy skin tests. This method is the most common in allergology, and is used to establish an accurate diagnosis.

Allergy tests are carried out for diseases such as:

bronchial asthma, manifested by repeated signs of suffocation as a result of spasm of the bronchi when exposed to allergens;
allergic dermatitis, characterized by rashes, redness and itching;
hay fever or allergy to pollen, which manifests itself as rhinitis, conjunctivitis, sneezing and runny nose;
food allergies, which are characterized by skin rashes, redness and itching.

How are skin tests done?

Skin tests for allergens can be done by scarification, with skin piercing (prick tests) and intradermal. In the first two cases, the procedure is quite simple. The doctor applies solutions of “interested” allergens to the skin of the patient’s back or forearm - no more than 15-20 per procedure. Under the drops, scratches are made using a special plate (scarification method) or shallow injections with a thin needle (prick method). You don’t have to languish in ignorance for long - the doctor evaluates the test results within 20 minutes.

Skin allergy tests are not performed:

during an exacerbation of any chronic disease (including allergies),
during acute infectious diseases,
children under 3 years old,
pregnant and lactating women.

In addition, it is not recommended for women to use this research method in the first days of the menstrual cycle. Due to hormonal changes occurring in the body, test results may be unreliable. In order to take an allergy test, the patient is asked to prepare in advance:

2 weeks before the procedure, stop taking internal antihistamines,

Stop using antiallergic ointments in a week.

Animal allergens: animal dander, mixture (general result): cats, horses, golden hamster, dogs

Individual allergens (1 allergen)

Food animal panel (individual result): lamb, beef, turkey, shrimp, chicken, salmon, cow's milk, goat's milk, egg white, egg yolk, pork, cheddar cheese, cod, tuna, hake

Diagnosis of allergic diseases is based on identifying a cause-and-effect relationship between clinical symptoms and certain factors in combination with positive results of allergy tests (allergy tests). Allergy tests are diagnostic measures to identify allergens - substances to which the body reacts negatively. He is working on solving this problem in the office of allergology and immunopathology of the Central Clinical Hospital of the Russian Academy of Sciences.

Indications for allergy tests

Frequent nasal congestion accompanied by discharge, not due to viral infections;
Itching in the nose or eyes for no apparent reason;
Rash on the body;
The skin is itchy or swollen;
Shortness of breath, cough, wheezing, or signs of suffocation occur suddenly;
There is a pronounced reaction to insect bites.

Food allergies;
Allergic dermatitis;
Drug allergies (in particular, to medications, to anesthetics in dental practice, to lidocaine, ultracaine);
Hay fever.

Contraindications

The patient is taking antihistamines;
With exacerbation of chronic diseases;
If the patient has had anaphylactic shock;
For pregnant and lactating women, menstruation is also prohibited;
AIDS;
Mental and nervous disorders;
Children and old age.

Types of allergy tests

The technology for conducting allergy tests depends on the type of allergens being tested and the type of allergic reaction. In vivo tests are performed directly on the patient and include:

Skin allergy tests

skin tests
intradermal tests
application or patch tests

The method involves identifying the allergen by applying the drug to the skin and recording the body's reaction. The method allows you to identify some infectious processes - brucellosis and tuberculosis. An adult (not older than 60 years) can carry out up to 20 tests per day. Children over 3 years old - up to two.

Skin tests can detect allergies to anesthesia.

Different groups of allergens are used to conduct skin tests:

Household - dust mites, library dust;
Pollen - on plant pollen;
Meadow grasses;
Weeds – ragweed, etc.;
Fungi, including mold;
Epidermal group: for a specific animal - for a dog, for mice, etc.

Provocative allergy tests

If all of the above studies do not produce results, provocative tests are used - the allergen is injected into the site of the allergic reaction. Allergy testing is carried out in a hospital.

TTEEL according to Ado

Test for inhibition of natural leukocyte emigration. The method consists of counting the number of leukocytes in the liquid before and after rinsing the mouth with a solution containing the drug to which an allergy is detected. The concentration of the drug is minimal so as not to harm the patient. If the number of leukocytes after rinsing has decreased by more than 30%, this indicates that the patient is intolerant to this drug. The method requires additional research.

Tests to diagnose urticaria

Laboratory blood tests
Nasopharyngeal swabs
Study of intestinal microflora
Thyroid function test
Allergy tests (tests for food and household allergens, fungal screening, inhalation screening)

Tests for diagnosing drug allergies.

To identify drug allergies, different types or a set of tests are used:

Laboratory blood tests
Prick testing
TTEEL according to Ado
Sublingual and oral provocation tests

In each type of test, the patient’s biological material is examined: blood from a vein, serum, sputum, broncho-alveolar lavage, etc. Modern laboratory diagnostic methods include:

identification of specific immunoglobulins of class E to various protein allergens using ELISA,
ImmunoCAP and ISAC,
in some cases, it is informative to determine the level of total immunoglobulin class E in the blood serum.

In vitro tests are laboratory tests of the body's sensitivity to an allergen. The patient's biological material is examined: blood, serum, sputum, broncho-alveolar lavage, etc. Modern methods of laboratory diagnostics include: identification of specific immunoglobulins of class E to various protein allergens using ELISA, ImmunoCAP and ISAC; in some cases, determining the level of total immunoglobulin of class E in blood serum is informative.

To diagnose atopic diseases (asthma, rhinitis, atopic dermatitis, conjunctivitis, allergies to insect venom), skin prick, scarification (scratch) and intradermal tests are performed to determine the level of specific IgE to the corresponding allergens.

If respiratory allergies (allergic rhinitis, asthma) are suspected, skin prick tests serve as a first-line diagnostic test. Determination of specific IgE levels and provocative tests are necessary in case of unclear diagnosis and sensitization to many allergens.

The main advantage of laboratory tests is the fact that their information content is not affected by the stage of the allergic disease, the condition of the patient’s skin, or the medications taken at the time of the study.

To diagnose delayed and delayed hypersensitivity reactions (allergic contact dermatitis, toxicoderma), application and intradermal tests and provocative tests are performed.

Where can I get allergy tests?

Make an appointment with an allergist-immunologist at the Central Clinical Hospital of the Russian Academy of Sciences in Moscow, where you can submit biomaterial and get a transcript of the results within one day. We welcome patients who suffer from allergies or simply want to make sure they do not react to certain medications, such as antibiotics or anesthesia, before surgery. We perform allergy tests quickly, accurately, and at an affordable price. An appointment with an allergist can be made by phone or online. How much it costs to take the type of allergy test you need is indicated in the clinic’s price list.

Cost for certain types of samples

Name of service	Price
Skin testing of reactions to allergens (atopic inhalant allergens)	2000
Skin tests for allergens (additional tests to clarify sensitization to atopic allergens)"	1200
Skin testing for allergens (extended spectrum of atopic inhalation allergens)"	2800
Intradermal studies of reactions to allergens (household, epidermal, fungal, food)	1600
Intradermal studies of reaction to allergens (test with autoserum)	2000
Skin allergy patch testing	6900
Study of specific Ig E to antigens of plant origin: panel of grass allergens (urchin, meadow fescue, perennial rye, timothy, meadow grass)	1100
Study of specific Ig E to food antigens: crack	500
Study of specific Ig E to food antigens: wheat flour	500
Study of specific Ig E to food antigens: peanuts	500
Study of specific Ig E to food antigens: soybeans	500
Study of specific Ig E to food antigens: hazelnuts	500
Study of specific Ig E to food antigens: crabs	500
Study of specific Ig E to food antigens: shrimp	500
Study of specific Ig E to food antigens: tomatoes	500
Study of specific Ig E to food antigens: carrots	500
Study of specific Ig E to food antigens: egg yolk	500
Study of specific Ig E to antigens of plant origin: panel of grass allergens (fragrant spikelet, perennial rye, cultivated, woolly broom, timothy, rye)	1100
Study of specific Ig E to food antigens: celery	500

Allergen tests are taken to determine the type of irritant. But before conducting a comprehensive examination, a consultation with a specialist is carried out. After all, in order to do an allergy test, it is necessary to take into account the patient’s age. Such tests are prohibited for children under 5 years of age.

Allergy symptoms

red rash on the skin. In addition, blisters filled with clear liquid may be observed. Areas localized by an allergic reaction itch and peel. Also, dermatological manifestations of allergies can change the affected area. This is very similar to contact or atopic dermatitis;
constant sneezing, dryness and congestion of the nasal sinuses;
increased lacrimation, redness of the eyes, irritation, pain and other signs of allergic conjunctivitis;
poisonous substance of stinging insects (bumblebee, hornet, wasp, bee). People who are susceptible to their stings are prone to severe allergy symptoms, including angioedema and anaphylactic shock;
neurasthenicity, fever, weakness, nausea.

In addition to all of the above, the patient may exhibit asthma of an allergic nature. Although examination of the clinical picture is not a direct test for allergens, it is rightfully considered a diagnostic measure. The fact is that when allergy symptoms appear, they have a clear connection with allergens.

Allergy stages

It is divided into immune, pathochemical, pathophysiological and clinical stages. The first begins from the initial moment of contact of the immune system with the irritant and lasts until the onset of increased sensitivity. The second is activated when the immune system comes into contact with allergens again, resulting in the release of bioactive elements.

At the third stage, the functions of soft tissues and cells are disrupted, and the last form is a continuation of this pathophysiological development. To prevent this, it is necessary to take timely measures.

In what cases are tests and samples needed?

The examination is carried out even if the body’s reaction to the allergen is weak, regardless of the nature of the immune response. It is extremely important for specialists to find out whether there is a genetic predisposition to the manifestation of pronounced symptoms with elevated levels of immunoglobulins. In addition, the presence of chronic and acute pathologies is revealed.

Skin tests and allergy prick tests make it possible to establish susceptibility to the following pathogens:

animal hair;
household dust;
medicines;
Food;
plant finger.

Laboratory diagnostic measures are necessary only in case of exposure to multiple irritants. If the reaction is vague, the chronic course of the disease cannot be qualified without specific tests. When the test results are received, the medical professional can with a high degree of probability tell what the person is allergic to.

It often turns out that the cause of unpleasant symptoms is cat litter, pets or dry fish food. But before taking a blood test for allergens, preparation is necessary. How to prepare for this procedure will be described further in the text.

So, how to prepare for an allergen test:

You need to take a blood test for allergens on an empty stomach.
Do not smoke several hours before the procedure. Smoking a cigarette can reduce the number of lymphocytes in the plasma.
3 days before the allergy test, avoid contact with pets.
For respiratory diseases, gastrointestinal disorders and other severe somatic pathologies, this procedure is not carried out. After complete recovery and after waiting another 3 days, tests are allowed.
Avoid intense physical activity and do not drink alcohol during the day.

After all the manipulations, you will receive a transcript of the blood test for allergies. Based on them, the amount of antibodies and the frequency of allergic symptoms will be visible.

Contraindications

The reliability of the results depends not only on high-quality preparation for the study, but also on taking into account limitations. In some cases, skin testing may cause significant harm to health or the data will be distorted.

Taking antihistamines

Antiallergic drops, tablets and suspensions reduce the quality of research. For a certain period before taking the tests, according to the instructions of the specialist, the patient must stop taking antihistamines. It is worth keeping in mind that in each case the period is set exclusively by a medical professional.

Exacerbation of attacks

During remission, provocative tests are not carried out, because the result against the background of an active reaction may not be entirely accurate. Also, these manipulations are postponed even during the most severe attacks. The only exception to the rule is an unexplained allergy that has been bothering a person for a long time.

Pregnancy

Expectant mothers are strictly prohibited from performing provocative tests and skin tests. Blood tests are not always accurate due to the high sensitivity of the body. But in practice, there are often cases when after the birth of the baby the allergic reaction stops. You can get rid of allergies on your own, you just need to watch your diet. If some product is to blame, it should be excluded.

Skin tests and blood tests for allergens are not taken in adults if they have severe illnesses. Similar manipulations are strictly prohibited for children under 5 years of age. They don’t even take blood tests for allergens from children.

Diagnostic result

After specialists have conducted a comprehensive examination, they can already tell which irritant provokes the symptoms of an allergic reaction. But in some cases there may be several such allergens. For example, it could be food, new food, pollen from different cultures.

Based on the tests obtained, the doctor will tell the patient:

what kind of disease is developing at the moment, and what stage it is at;
how to properly create a hypoallergenic diet menu;
what medications should be avoided;
you can come into contact with pets or you will have to say goodbye to them (give them into good hands);
how to properly clean your home in order to minimize dust and the subsequent proliferation of dust mites;
will prescribe medications for the treatment of allergies that occur in acute or chronic form.

Among other things, the specialist will tell you about preventive measures.

Types of examinations

General blood analysis

In fact, this is a very important analysis that allows you to diagnose the general well-being of the patient. Blood, performing a transport function, comes into contact with almost all systems of internal organs. Its total examination leads to complete awareness of the condition of the internal organs.

First of all, the doctor pays attention to the increased level of neutrophils, eosinophils, and basophils. This tends to manifest itself with a tendency to develop an allergic reaction and the development of an acute serious illness. In addition, the erythrocyte sedimentation rate is monitored, which only confirms the presence of an inflammatory focus in the body. Against this background, allergies are extremely difficult.

Determination of the content and detection of immunoglobulin antibodies “G”, “E”

This is a highly sensitive diagnostic method that allows you to accurately determine the presence of a predisposition to various types of allergies. Patients who do not suffer from hypersensitivity of the body contain a critical amount of E-immunoglobulin in the blood. The presence of specific antibodies indicates the development of an allergic reaction. The main advantage of this research method is the ability to collect blood with accurate results during exacerbation and remission. It is allowed to be carried out at absolutely any age: children, the elderly. And also during pregnancy.

Elimination tests

This method is mainly recommended when negative signs occur periodically. What is elimination? This is the exclusion of the intended stimulus for a certain period of time. This technique has proven effective in testing for food allergies. During an elimination diet, foods that caused allergies were excluded from the menu for several weeks. If the patient's condition has noticeably improved, the test confirms the guess.

Conducting skin tests, provocative tests

Determination of allergens is carried out using scarification or injections. These manipulations are performed in the forearm area. After disinfection, the physician makes a slight, shallow injury to the upper layer of the epidermis and applies a small amount of the suspected allergen. If after 15-20 minutes swelling, redness appears, the conclusion is that these are the allergens that cause a lot of inconvenience to the patient. If the skin is highly sensitive, a patch test is done (paste a patch that has been previously impregnated with an allergen). Fifteen scratch tests or peak tests can be done at one time.

Features of taking tests in a child

As a rule, children undergo the same allergen tests as adults. Therefore, skin tests and blood tests are used. But since the child’s reaction can be strong, all manipulations are carried out under the total supervision of a medical professional. During one such procedure, only five potential tests to identify allergens are allowed.

It is important to have information that in some cases there are contraindications for blood tests for children under 3-5 years of age. First of all, it depends on the severity of the clinical picture. If an allergic reaction occurs in an infant who is breastfeeding, there is no point in conducting a general blood test. Mom needs to be examined. In older children, allergies can be caused by synthetic clothing, physical activity, stressful situations, constant humidity (temperature changes), etc.

In addition to itching and a red rash, the skin begins to peel off and thicken. Fungal infections of the skin and mucous surfaces can complicate the course of allergies. If you are sensitive to antibiotics or egg whites, you may be allergic to the rubella, measles and mumps vaccine. The reaction appears 3 days after vaccination.

Pet allergy test

Some people assume that short-haired animals cannot be allergic; it is worth upsetting them. The fact is that allergies can be triggered not only by fur, but also by feces, urine, and saliva. In this case, two analyzes are carried out, which were described earlier, so repeating them in each paragraph does not make much sense.

Analysis for food allergies

Allergenic products are generally considered to be:

strawberry;
fish, seafood;
milk protein;
products containing excessive amounts of flavorings, sensitizers and other harmful additives;
exotic vegetables and fruits;
spices.

During one procedure, an adult patient is allowed to inspect 10-300 types of suspected allergens.

Scale for assessing the body's reaction:

High (more than 5000 ng/mg). Eliminate the product from the diet urgently.
Moderate (1000-5000 ng/mg). The product can be consumed only once every 7 days.
Low (less than 1000 ng/mg). This means that there is no allergic reaction to this product, it is allowed to be eaten at least every day.

When all the results are received, the specialist will prescribe a full course of treatment. If the allergy bothers you for a very long time and independent research does not help, immediately contact a medical facility.