Home » Dentistry » Carrying out skin tests for allergens. Allergy skin tests What are allergy skin tests

Carrying out skin tests for allergens. Allergy skin tests What are allergy skin tests

Skin tests are included in the allergy examination program for patients. of different ages. They are used to detect allergens that provoke pathological changes in the body and prescribe allergen-specific treatment.

The test consists of applying a small amount of the suspected allergen to a certain area of the skin and examining it by a doctor after some time. The occurrence of redness and swelling in this area is considered positive reaction, indicating the body's sensitivity to the allergen. The resulting redness and swelling are assessed and measured to determine the degree of sensitivity to the allergen component.

There are several techniques for performing skin tests.

Scarification - tests involving scratching the skin.
Intradermal - the allergen is introduced into the upper layer of the skin.
Application - the allergen component is applied to the surface of the skin. These are closed and open patch tests used to detect delayed-type hypersensitivity in contact dermatitis.
Prick tests - piercing the skin with a needle (prick test).

The main indications for prescribing skin tests to a patient are:

bronchial asthma;
rhinitis that cannot be treated with medication;
suspected food, drug and insect (caused by insects) allergies;
atopic dermatitis;
acute and chronic urticaria, conjunctivitis (in children);
reactions to insect bites, anaphylaxis (in children).

Contraindications for patient participation in skin testing include:

extensive pathological changes in the skin;
urticarial dermographism;
severe somatic diseases in the stage of decompensation;
impossibility of discontinuing medications that may affect the results of allergy tests;
mental disorders;
age less than 2 years (due to difficulties in interpretation);
risk of developing anaphylactic shock;
pregnancy.

Allergy tests (or allergy tests) are diagnostic techniques for identifying individual intolerance to various substances (i.e., allergens). Their appointment can significantly help in eliminating allergic reaction and allows you to set the maximum number of allergens. This article provides information on methods, indications, contraindications, methods of preparing and passing allergen tests. The data obtained will allow you to get an idea of such diagnostic techniques, and you will be able to ask your attending physician any questions you may have.

Such tests are recommended by specialists to every allergy sufferer, since the tests make it possible to compile a so-called black list of those irritants that disturb the state of balance. immune system. The results of allergy tests allow you to exclude contact with allergens, create the necessary diet and prescribe the most effective treatment.

Indications

Occurs frequently, not associated with viral diseases Nasal congestion is an indication for allergy testing.

In some cases, it is impossible to determine the type of allergen through normal observation of diet and environmental factors. In such situations, the doctor recommends allergy tests using one or another method. The following patient complaints may be indications for such studies:

unreasonable frequent nasal congestion and discharge from it;
gratuitous or nasal;
constant presence on the body, accompanied by itching;
swelling of the skin;
sudden attacks of suffocation, wheezing, shortness of breath, difficulty breathing, or a suffocating cough;
the appearance of an allergic reaction to (itching, redness, swelling of the skin, rash, difficulty breathing).

Some experts recommend conducting allergy tests for periodic dyspeptic disorders (vomiting and stomach pain) or dry skin. Their implementation makes it possible to exclude or confirm the presence of allergic reactions and can be a differential diagnostic method for other diseases with similar symptoms.

All of the above symptoms may indicate the presence of such allergic reactions:

and/or conjunctivitis;
(rash, itchy skin, dyspepsia);
allergies to medications.

The main purposes of prescribing allergy tests

The purposes of prescribing allergen tests are aimed at:

eliminating the allergen or prescribing effective treatment;
identifying an allergic reaction to a cosmetic product or product household chemicals;
testing of new prescribed drugs.

Tests to identify individual intolerance to drugs or household chemicals and cosmetics help prevent the development of an allergic reaction, and tests to identify an allergen help to identify not only suspected irritants, but also identify unknown substances that can provoke allergies. Performing such tests allows you to choose a way to combat allergies:

Complete elimination of contact with the allergen is the most effective method, but not always possible;
appointment of SIT ( specific immunotherapy allergens) – the most effective way treatment, but requires systematic annual repetition of courses for 3-4 years;
Symptomatic therapy does not cure allergies, but helps eliminate its symptoms.

Types of allergy tests

There are many methods for performing allergy tests. One or more of them can be used for diagnosis.

Most often, allergy patients are prescribed the following two types of tests:

comprehensive allergy test using immunological blood tests;
skin allergy tests.

In more rare cases, provocative tests are performed.

Immunological blood tests

Such allergy tests make it possible to detect the presence of an allergic reaction even to early stages its manifestations and identify allergens. For this purpose, the following methods can be prescribed:

analysis for total immunoglobulin E (IgE);
tests for specific immunoglobulin E (IgE);
ImmunoCap tests.

The principle of these laboratory research is based on identifying in the blood and determining the level of antibodies - immunoglobulins E and G, formed in response to exposure to allergens.

Analysis for total IgE

Such immunological blood tests are prescribed for children or adults if the following diseases are suspected:

bronchial asthma;
bronchopulmonary aspergillosis;
dermatitis;
individual intolerance to certain foods;
individual intolerance to certain medications, etc.

In addition, such an analysis can be prescribed to children whose parents are prone to allergic reactions.

Blood is drawn from a vein after the necessary preparation:

Tell your doctor about everything you take medicines.
A few days before donating blood, stop eating highly allergenic foods (eggs, chocolate, strawberries, etc.), alcoholic drinks, fatty and spicy dishes.
3 days before the study, all physical and psycho-emotional stress is excluded.
In the morning before blood sampling, you should not drink or eat.
Stop smoking an hour before the test.

If the test results for total IgE reveal an increase in its level, this indicates the presence of an allergic reaction.

Normal levels of IgE in the blood:

children from 5 days to 1 year – 0-15 kU/ml;
children from 1 to 6 years old – 0-60 kU/ml;
children from 6 to 10 years old – 0-90 kU/ml;
children from 10 to 16 years old – 0-200 kU/ml;
over 16 years old and adults – 0-100 kU/ml.

Analysis for specific IgE and IgG4

The level of immunoglobulins is determined in the patient’s blood taken from a vein.

This test identifies one or more allergens that cause an allergic reaction. This laboratory diagnostic method is prescribed to people of any age for:

the impossibility of determining the factor that provokes the allergy based on observations and clinical picture;
widespread dermatitis;
the need to establish a quantitative assessment of sensitivity to an intolerable substance.

The principle of performing such an immunological allergy test is to mix samples of serum obtained from blood with allergens (for example, pollen, animal dander, household dust, detergents etc.). The results of the analysis can be demonstrated by reagents: enzymes (for the ELISA test) or radioisotopes (for the RAST test). To carry out the analysis, blood is donated from a vein on an empty stomach, and the principle of preparing for the study is similar to preparing for donating blood for total IgE.

This method of identifying allergens is completely safe for the patient, since he does not come into direct contact with causing allergies substance and does not receive additional sensitization. The following basic allergen panels can be used for analysis:

allergy screening for 36 allergens: hazel pollen, white birch, Kladosporium and Aspergillus mushrooms, black alder, quinoa, fescue, dandelion, rye, wormwood, timothy, bird feathers (mixture), horse, cat and dog hair, household dust, cockroach, mixture cereals (corn, rice and oats), beef, chicken egg, chicken meat, pork, tomato, carrot, strawberry, apple, cod, cow's milk, potatoes, hazelnuts, soybeans, peas, wheat;
allergy screening for 20 allergens: ragweed, wormwood, white birch, timothy, Kladosporium, Alternaha and Aspergillus mushrooms, D. Farinae mite, D. Pterony mite, latex, cod, milk, egg white, soy, peanuts, wheat, rice, cat hair , dogs and horses, cockroaches;
IgE food panel for 36 food allergens: white beans, potatoes, banana, orange, raisins, mushrooms, cabbage mix (white, cauliflower and broccoli), celery, wheat, carrots, garlic, almonds, peanuts, walnut, chicken meat, beef, turkey, egg white, egg yolk, pork, cod, tuna, cow's milk, onion mixture (yellow and white), yeast, soybeans, rye, tomatoes, rice, pumpkin, seafood mixture (shrimp, mussels, crab), chocolate.

There are many different allergy panels, and the choice of one or another technique is determined by the doctor individually. In some cases, the patient may be recommended to donate blood to a list of allergens determined by a specialist individually (the so-called in-depth allergy screening), a fungal panel (includes about 20 of the most common molds), a card of alcohol allergens or a MIX panel (for 100 allergens).

The results of the analysis for specific IgE and IgG4 reflect the sensitivity to a particular allergen in the panel:

up to 50 U/ml – negative;
50-100 U/ml – low sensitivity;
100-200 U/ml – moderate sensitivity;
above 200 U/ml – high sensitivity.

The duration of the tests can be several days (depending on the laboratory).

ImmunoCap tests

In the most difficult diagnostic cases, patients suffering from allergies may be recommended to undergo ImmunoCap tests. These methods allow not only to determine the intolerable substance, but also to identify the presence of a cross-reaction between different types of molecules and “calculate” the most major (i.e., malicious) allergen.

Preparation for performing such tests is similar to the procedure for preparing for analysis for total IgE. However, to perform it, it is necessary to take a larger volume of blood, which excludes the use this method for examination of infants.

When prescribing an ImmunoCAP test, a patient may be recommended one or more allergy panels:

pollen;
food;
mite allergens;
tick;
inhalation Phadiatop;
food fx 5;
polynosis MIX;
timothy grass (mixture);
timothy, wormwood, ragweed;
early spring herbal mixture;
atopy MIX;
fungal molecular 1 or 2;
ambrosia;
household;
autumn-wormwood.

The duration of the tests can be about 3 days (depending on the laboratory).

Skin allergy tests

An allergy skin test involves applying allergens to the skin and then assessing the skin's reaction to each substance.

Such allergy tests will allow you to quickly identify increased sensitivity to various substances by applying them to the skin and assessing the intensity of the inflammatory skin reaction. Sometimes such tests are performed to identify certain infectious diseases– tuberculosis and brucellosis.

In one day, 15-20 skin allergy tests with different allergens can be performed. A 5-year-old child can be tested with only two drugs at a time. Such tests can be performed on adults up to 60 years of age, and they are prescribed to children only after reaching 3-5 years of age.

The following types of skin allergy tests can be used for diagnosis:

qualitative (or prick tests) - detect an allergic reaction to a certain substance;
quantitative (or allergometric testing) - determine the strength of the allergen and indicate the amount of intolerable substance that causes an allergic reaction.

Typically, such tests are performed on the flexor surfaces of the forearms, and in some cases on the back.

Before performing such allergy tests, the patient is recommended to prepare for the study:

Tell your doctor about all medications you take and previous illnesses.
14 days before the tests, stop taking glucocorticosteroids (internally and externally).
Stop taking it 7 days before the test.
Have a snack before performing the study.

High-quality skin allergy tests can be performed using the following methods:

drip – a drop of the allergen is applied to the skin and the result is assessed after a certain time (performed only for small children);
application - pieces of fabric soaked in the allergen are applied to the skin;
scarification - scratches or micropunctures are made on the skin with a needle or scarifier, onto which the allergen is applied;
injection - intradermal injections are performed using an insulin syringe with an allergen solution.

Most often, the scarification method is performed. The study is carried out in a specialized department of the clinic, where, if necessary, the patient can receive urgent Care, or in a hospital.

To perform skin tests, different lists of allergens are used:

household: daphnia, library dust, house dust mites, etc.;
pollen: hazel, birch, alder;
meadow and cereal grasses: timothy, cocksfoot, rye, oats, etc.;
weeds: ragweed, nettle, wormwood, white pigweed, dandelion, etc.;
fungi: mold, etc.;
epidermal: rabbits, cats, dogs, mice, parrots, horses, rats, etc.

Methodology for performing a high-quality allergy test:

The skin is treated with alcohol.
After drying, allergens are marked on the skin (by number) using a hypoallergenic marker.
A drop of the corresponding allergen (or pieces of tissue soaked in the allergen during an application test) is applied near the marks.
A neutral test control solution is applied to a separate area.
When performing a scarification test, small scratches (up to 5 mm) or punctures (no more than 1 mm) are made with a needle or scarifier. A separate needle or scarifier is used for each drop of allergen.
The doctor begins to monitor the condition of the skin and general condition patient.
The final assessment of results is performed after 20 minutes and 24-48 hours.

The rate of onset of an allergic reaction is assessed by the following indicators of the appearance of redness or a blister:

instantly – positive reaction;
after 20 minutes – immediate reaction;
after 24-48 hours – slow reaction.

In addition, the skin reaction is assessed on a scale from “-” to “++++”, which reflects the degree of sensitivity to the allergen.

After completion of the study, the patient must be under medical supervision for 1 hour.

What can affect the reliability of the results?

In some cases, allergy skin tests can give false or false-positive results:

improper execution of skin scratches;
decreased skin reaction;
taking medications that can reduce the rate of an allergic reaction;
improper storage of allergen solutions;
allergen concentration is too low;
too close location of skin scratches (less than 2 cm).

Provocative tests

Provocative tests for exposure to allergens are performed in rare cases. They can be prescribed only when all other allergy tests “do not work” and signs of an allergic reaction remain. The principle of their implementation is based on the introduction of an allergen to the place where signs of the disease clearly appear.

Provocative tests are as follows:

conjunctival - used to detect allergic conjunctivitis by injecting an allergen solution into the lower conjunctival sac;
inhalation – used to detect bronchial asthma by introducing an aerosol of an allergen into the respiratory tract;
endonasal - used to identify allergic rhinitis or polynosis by instilling an allergen solution into the nasal cavity;
temperature (cold or heat) - used to identify thermal or cold urticaria by performing a particular temperature load on a certain area of the skin;
elimination – consist in completely limiting the patient from food or drug allergens;
exposure – consist of ensuring direct contact of the patient with the suspected allergen;
thrombocytopenic and leukocytopenic - involve the introduction of a food or drug allergen and after some time performing an analysis of the level of leukocytes and platelets in the blood.

Such tests can only be carried out in a hospital setting, and solutions of these substances in a dilution of 1:1000 are used as an allergen.

Contraindications to allergy tests using allergens

In some cases, performing any tests using allergens is contraindicated:

reception antihistamines(Diazolin, Tavegil, Loratadine, Zyrtek, Erius, etc.) - an allergen test can be carried out only a week after their cancellation;
the occurrence of an acute or exacerbation of a chronic disease - the study can be performed after 2-3 weeks;
exacerbation of allergies - the test can be performed 2-3 weeks after the cessation of all symptoms;
reception sedatives(valerian, motherwort, Persen, Novo-passit, bromine salts, magnesium, etc.) - analysis can be performed 5-7 days after their discontinuation;
taking glucocorticoids - the test can be carried out 2 weeks after their discontinuation;
a history of anaphylactic shock;
period of menstruation, pregnancy or lactation;
and other immunodeficiencies;
intense acute reaction to an allergen;
autoimmune diseases;
mental disorders, some diseases nervous system, convulsions;
severe course

The body's sensitivity to certain aggressive substances is determined by conducting allergy tests. This is a research method in which an allergen is applied to the skin or mucous membranes, after which the reaction to it is studied. Usually prescribed in case of frequent symptoms, in the presence of a rash, and also before the use of anesthesia.

General information

Allergy tests, or allergy tests, are considered to be the maximum precise method diagnostics of body sensitization. When performing them, they take standardized allergens that have been approved for use. Once on the skin or under the skin, depending on the research method, they begin to interact with special cells that ensure their transport to mast cells.

If after this there is a release of allergy mediators and the development of a local allergic reaction in the form of a rash, redness, the administered chemical substance recognized as an allergen.

Before prescribing allergy tests, a complete examination of the body is performed. Due to the fact that this research method is associated with the risk of developing severe allergic reactions, it should be carried out in a specialist’s office under his supervision.

Indications for allergy testing

Allergy tests are carried out for both adults and children in the following cases:

development, manifested by regular attacks of suffocation due to bronchospasm provoked by allergens;
accompanied by redness of the skin, rash, itching;
, expressed by sneezing when inhaling pollen;
drug allergies, expressed by rash, itching of the skin and mucous membranes;
- most often accompanied by skin rashes, although it is also possible - indigestion with the occurrence of discomfort and pain in the stomach.

Patient complaints for which the doctor can write a referral for allergy tests:

causeless, runny nose, which appeared repeatedly;
itchy eyes or nose;
a rash on the body that causes itching and does not go away for a long time;
swelling of the mucous membranes or skin;
difficulty breathing, causeless attacks of suffocation, wheezing;
redness and swelling of the skin, rash, difficulty breathing due to an insect bite;
dry skin.

Such tests are primarily carried out to identify and exclude an allergen that undermines the immune system and worsens a person’s quality of life. In addition, they can be used to test new cosmetic products, as well as household chemicals.

Types of allergy tests

There are several types of tests to detect allergies. The choice of each of them is made by the doctor based on the patient’s complaints.

Most often, the doctor gives preference:

immunological;
skin allergy tests.

Due to the fact that skin tests do not give a 100% result, the allergist usually prescribes a blood test. In this case, antibodies to allergens are detected, which make it possible to diagnose an allergic reaction.

It is worth noting that blood tests are especially important if the allergy develops rapidly, within an hour. Then each new contact with an allergen can provoke the development of more severe consequences for the body.

Please note

There is also the concept of provocative tests. These are tests in which substances are applied directly to the conjunctiva or to the mucous membranes of the nasal cavity, for example, at the time of inhalation, and thereby provoke redness, itching, nasal congestion, and sneezing.

Such diagnostics make it possible to determine the presence of an allergic reaction at its first manifestations.

The use of the following techniques is implied:

tests for total immunoglobulin E;
tests for specific immunoglobulins;
ImmunoCap tests.

The essence of such studies is to detect immunoglobulins E and G in the blood - these are antibodies that are formed in response to allergens entering the body.

Total IgE test

Prescribed to children and adults when they have:

The total IgE test is performed by drawing blood from a vein. Before the procedure, you should not eat or drink in the morning. Any medications you take during this period should be reported to your doctor in advance.

Preparation for diagnosis includes:

refusal of alcohol, fatty and spicy foods, as well as foods that can cause allergies (chocolate, citrus fruits, egg whites) a few days before the date of the event;
emotional and physical calm 3 days before the analysis (not recommended physical activity, stress);
quit smoking 60 minutes before the test.

Norms:

Tests for specific IgE and IgG4

Such methods are used when the clinical picture does not allow one to determine which allergen provokes the development of an allergic reaction. They are also prescribed for common dermatitis.

The essence of the tests comes down to mixing blood serum with allergens - pollen, animal saliva, dust, cosmetics. Additionally, enzymes and radioisotopes are used. If the rules of the procedure described in the previous subsection are followed, the specialist receives accurate results.

Please note

The main advantage of the test for specific immunoglobulins IgE and IgG4 is that it does not require patient contact with allergens. Thus, a safe and informative study is carried out.

In this case, the doctor may recommend a specific allergy panel(food, fungal, alcohol allergen panel) depending on the medical history. Each of these panels includes from 20 to 100 allergens, the sensitivity to which is studied. If necessary, in-depth allergy screening is performed, when a specialist selects several substances, individually, to conduct the test.

Such diagnostics can take several days, depending on the work of the laboratory.

Norms:

ImmunoCap tests

They are carried out in cases where conventional diagnostics do not allow accurate results to be established. Their advantages lie in the ability to detect intolerant substances, as well as cross-reactions between molecules different types and determining the most powerful allergen.

Preparing for this analysis is no different from preparing for previous tests. However, due to the fact that a larger volume of blood is needed for the study, it is not prescribed to young children.

The procedure can take up to 3 days. It allows you to identify allergies to pollen, food, mites, fungi, plants, and dust.

Skin allergy tests

When conducting skin allergy tests, allergens are applied to the skin, after which a specialist observes its reaction. No more than 15–20 samples can be used at a time. Moreover, it is permissible to carry out the analysis on children and adults aged 3 to 60 years.

Please note

At 5 years of age, it is permissible to test with only two allergen solutions.

According to the type of skin allergy tests, they are distinguished:

Allergens are applied to the forearms (where the arm bends), and rarely to the back. It is recommended to have a snack before the procedure. The doctor must also be informed about all medications that are currently being taken. A week before the test, you should stop taking glucocorticosteroids, and 2 weeks before the test.

There are several ways to perform high-quality allergy tests:

Regardless of the method of performing allergy tests, all tests are carried out in a specialized institution, where, if necessary, the patient can receive qualified medical care.

The methodology for conducting high-quality allergy tests includes the following steps:

Treating the skin with alcohol.
Applying markings that will distinguish different allergens.
Directly performing the test is applying a drop of an aggressive substance or applying a cloth with it. If a scratch test is selected, scratches up to 5 mm long or small punctures of the skin (up to 1 mm) are made.
Monitoring the patient's skin condition and well-being.
Evaluation of results - the stage can last for a period from 20 minutes to 48 hours.

The test result depends on how quickly redness or blisters appear on the skin.

Additionally, the marks “-” and “+” reflect the degree of sensitivity to the aggressive substance. At the end of the procedure, the patient is recommended to remain within the walls of the medical facility for another hour.

Reasons for false results

False positive or false negative test results occur if:

the analysis technique is violated - for example, when scratches are made incorrectly (too close to each other - at a distance of less than 20 mm);
the rate of manifestation of an allergic reaction decreases due to taking antihistamines;
the rules for storing allergen drugs are violated;
the specialist applies/introduces too low a concentration of the substance.

Provocative tests

In medical practice, there are cases when the usual allergy tests do not reveal an allergic reaction, yet its signs are present. Then the doctor decides to conduct provocative tests. The principle of their action comes down to the introduction of the allergen precisely into the area in which the allergic reaction is most pronounced.

The term “skin tests for allergies” refers to a method for determining an allergen, characterized by the highest possible information content. The relatively simple technique is effective and brings virtually no discomfort to the patient. Before starting the test, it is important to find out all the indications for use, as well as contraindications. In addition, it is necessary to properly prepare for skin prick tests, scarification tests, and special applications.

An allergic reaction may be caused by huge amount factors and substances, including:

alcohol;
mold and all types of fungus;
flower pollen;
most food products;
cosmetics and household chemicals;
wool;
ultraviolet;
medicines and so on.

The symptoms of an allergic reaction do not depend on the irritant, so it is often quite difficult to identify the allergen through questioning and examination.

In some more complex cases, the human immune system is sensitive to several allergens at the same time, which further complicates the final diagnosis.

The following symptoms are considered indications for skin testing:

allergic cough and asthma;
skin irritations, including eczema, hives, rashes;
itching of mucous membranes and skin;
nasal congestion, runny nose, ;
migraines, headaches, dizziness;
conjunctivitis;
nervous system disorders, dizziness;
disruptions in the gastrointestinal tract, constipation and diarrhea;
Quincke's edema and so on.

Before you learn how skin tests for allergies are done, you need to understand in what cases the test is performed. The technique helps to identify the irritant:

If the irritant has had contact with the skin of an allergic person, accompanied by interaction with mast cells;
If allergic symptoms occur when the irritant penetrates the wound;
If an area of skin becomes itchy, swollen and red as a result of the applied allergen.

As a result of the test, the doctor determines the irritant or group of irritants that it is important for the allergic person to exclude from everyday life.

Mandatory elements of this diagnostic method include extracts and solutions of various allergens. To ensure that the result of the study is extremely pure, doctors use histamine and glycerin. A larger number of tests show a response to histamine, since the absence of any response on the skin most often indicates an error in the test. The test is carried out using a tampon applicator, lancet or a special needle.

Skin tests for allergies: contraindications

It is prohibited to carry out this study in the following cases:

when an allergy sufferer suffers from infectious diseases, including sore throat, bronchitis, pneumonia and so on;
when the patient is diagnosed with AIDS or any other autoimmune pathology;
when the risk of occurrence is high;
during pregnancy or lactation;
if an allergy sufferer suffers from mental disorders;
when a malignant neoplasm is diagnosed.

Experts subdivide everything possible contraindications into two groups: absolute and relative. Some diseases are considered relative contraindication, in which it is strictly forbidden to introduce the irritant even in minimal doses. However, the study can be carried out after complete recovery or the birth of a child. If there are absolute contraindications, the diagnosis should be changed to a highly informative and safe blood test.

Species

Today there are several types of skin tests:

scarification. The doctor applies a small amount of concentrated irritant to the allergy sufferer’s forearm, after which he makes short scratches with a lancet or needle;
application. This type of skin test does not imply the need to injure the epidermis. A tampon, previously moistened in a concentrated solution of the irritant, is applied to the patient’s skin;
prick test. A drop of the allergen is applied to the patient’s skin, after which the doctor uses a special needle to make a puncture.

How to prepare for the analysis?

How are allergy skin tests done? In order for the analysis results to be extremely accurate, the patient must be properly prepared before the study. Experts recommend taking several tests before taking skin samples, or rather biochemical and clinical analysis blood, coprogram, general analysis urine.

In addition, ten days before the planned date of the study, the allergy sufferer must stop taking any medications that distort the results. These medications include antidepressants, antihistamines and so on.

Results

The results of skin tests can be considered negative if the skin does not react in any way after applying the concentrated irritant. However, the answer can also be considered a false negative if there are no manifestations on the skin at all. In this case, it is recommended to repeat the study.

If the skin itches, turns red or swells upon contact with an allergen, the test result can be considered positive. The response to the stimulus can appear either after a few hours or after a few days. The diagnosis also directly depends on the intensity of the reaction.

A weak result is considered doubtful if the weak reaction does not coincide with the symptoms. In this case, the study must be confirmed; for this purpose, provocative tests or blood serum testing are performed. If, in the presence of clinical symptoms, antibodies are detected in the serum as a result of the analysis, the skin test reaction becomes positive. Most often, tests give erroneous answers if you do not prepare for them correctly.

To eliminate the possibility of error, doctors often apply pure histamine to the epidermis before the test and only then a drop of the irritant. If the skin reacts to histamine with redness, but does not react to the allergen at all, the answer can be considered infallible.

Statistics show that every tenth allergy sufferer receives inaccurate results after conducting a skin test.

Side effects

Skin tests for allergies in children and adults, like any other medical procedure, can cause side effects, which include swelling, redness, itching, rashes, blisters, and so on.

The listed symptoms in most cases disappear within a few hours after the test, but sometimes they can persist for up to two to three days. To get rid of unwanted side effects, it is enough to use ointments that contain cortisone.

As a rule, following the rules for conducting the test, as well as preparing for it, allows you to completely avoid side effects. This is especially true when it comes to exacerbation of the disease. Therefore, it is strictly forbidden to conduct research when allergic symptoms are pronounced.

Price

Skin tests for allergies can be taken in a regular public hospital after an appointment with an allergist or in any private clinic. As a rule, the cost of the analysis depends on the number of allergens involved in the study, as well as on the quality of the reagents used.

In extremely rare cases, skin testing can cause a serious allergic reaction that can only be treated by a medical professional. This kind of side effects As a rule, they are immediate, so immediately after the test the patient must remain under medical supervision for some time.