What are the main types of allergy tests. How accurate are skin prick tests versus blood tests. When should you see an allergist for allergy testing. What factors can affect allergy test results.

Understanding Allergy Testing: A Crucial Step in Diagnosis

Allergy testing is a vital component in the diagnosis and management of allergic conditions. It allows healthcare professionals to identify specific allergens triggering a patient’s symptoms, enabling targeted treatment strategies. Both adults and children can undergo allergy testing, often as early as the first consultation with an allergist.

Once the results are available and a diagnosis is made, the allergist can provide detailed information about the patient’s allergies and recommend appropriate treatment options. The two primary methods of allergy testing are skin tests and blood tests, each with its own advantages and applications.

Why is allergy testing important?

Allergy testing is crucial because it helps:

• Identify specific allergens causing symptoms
• Guide targeted treatment plans
• Prevent unnecessary avoidance of harmless substances
• Improve quality of life for allergy sufferers

Skin Testing: The Gold Standard in Allergy Diagnosis

Skin testing is considered the gold standard for allergy diagnosis and is preferred by trained allergists due to its accuracy and quick results. This method involves exposing the skin to small amounts of potential allergens and observing the body’s reaction.

Types of Skin Tests

There are two main types of skin tests used in allergy diagnosis:

1. Prick or scratch test (percutaneous test): A tiny drop of a potential allergen is pricked or scratched into the skin’s surface. This is the most common type of skin test.
2. Intradermal test: A small amount of the suspected allergen is injected under the skin using a thin needle. This test is typically used for specific allergies, such as insect stings or penicillin reactions.

How accurate are skin prick tests?

Skin prick tests are generally highly accurate when performed and interpreted by trained allergists. Their accuracy can vary depending on factors such as:

• The specific allergen being tested
• The quality of the allergen extract used
• The skill of the person performing the test
• The patient’s individual skin reactivity

When conducted properly, skin prick tests have a sensitivity of 70-95% and a specificity of 80-97% for most common allergens.

Blood Testing: An Alternative Approach to Allergy Diagnosis

Blood tests, also known as in vitro tests or specific IgE tests, are another method used to diagnose allergies. These tests measure the levels of specific antibodies (IgE) in the blood that are produced in response to allergens.

Advantages of Blood Tests

Blood tests offer several advantages in certain situations:

• They require only a single needle prick
• Medications do not interfere with the results
• They are safer for patients with severe skin conditions or a history of anaphylaxis
• They can be performed when skin tests are not practical or available

Are blood tests as accurate as skin tests for allergies?

While blood tests can be useful in certain situations, they generally have lower sensitivity and specificity compared to skin tests. The accuracy of blood tests can vary depending on the specific allergen and the test method used. Some studies have shown that blood tests have a sensitivity of 70-90% and a specificity of 80-95% for common allergens, which is slightly lower than skin tests.

The Role of Allergists in Allergy Testing and Diagnosis

Board-certified allergists play a crucial role in the accurate diagnosis and management of allergies. These specialists are trained to select the most appropriate tests based on a patient’s specific symptoms, environmental exposures, and medical history.

Why should you see an allergist for allergy testing?

Consulting an allergist for allergy testing offers several benefits:

• Expertise in test selection and interpretation
• Comprehensive evaluation of symptoms and medical history
• Ability to differentiate between clinical allergies and sensitization
• Development of personalized treatment plans
• Access to the most up-to-date allergy management strategies

Factors Affecting Allergy Test Results

Several variables can influence the accuracy and interpretation of allergy test results. Understanding these factors is crucial for both healthcare providers and patients.

What can affect the accuracy of allergy tests?

The following factors may impact allergy test results:

• Medications: Certain medications, particularly antihistamines, can interfere with skin test results
• Skin conditions: Severe eczema or other skin disorders may affect the skin’s reactivity
• Age: Very young children and older adults may have reduced skin reactivity
• Recent severe allergic reactions: These can temporarily reduce skin reactivity
• Cross-reactivity: Some allergens share similar proteins, leading to false-positive results
• Quality of allergen extracts: Variability in extract potency can affect test results

Interpreting Allergy Test Results: Beyond Positive and Negative

Interpreting allergy test results requires expertise and consideration of the patient’s clinical history. A positive test result alone does not necessarily indicate a clinically relevant allergy, and a negative result does not always rule out an allergy.

How are allergy test results interpreted?

Allergists interpret test results by considering:

• The size of the skin reaction or level of specific IgE in blood tests
• The patient’s reported symptoms and their correlation with exposure to specific allergens
• The likelihood of cross-reactivity between similar allergens
• The overall clinical picture, including medical history and physical examination findings

This comprehensive approach helps differentiate between true allergies and sensitization without clinical relevance.

Allergy Testing for Specific Allergens

Allergy tests can be performed for a wide range of common allergens, including environmental, food, and drug allergens. The selection of specific allergens to test is based on the patient’s history and suspected triggers.

What allergens can be tested for?

Common allergens that can be tested include:

• Environmental allergens: Pollen, dust mites, mold spores, animal dander
• Food allergens: Peanuts, tree nuts, eggs, milk, wheat, soy, fish, shellfish
• Insect venom: Bees, wasps, hornets, fire ants
• Medications: Penicillin and other antibiotics
• Latex

The specific panel of allergens tested may vary based on regional prevalence and individual risk factors.

The Future of Allergy Testing: Emerging Technologies and Approaches

As our understanding of allergies evolves, new approaches to allergy testing are being developed. These advancements aim to improve diagnostic accuracy, patient comfort, and the ability to predict severe reactions.

What new allergy testing methods are being developed?

Emerging allergy testing technologies include:

• Component-resolved diagnostics (CRD): This technique identifies specific molecular components of allergens, allowing for more precise diagnosis and risk assessment
• Basophil activation tests (BAT): These tests measure the activation of basophils (a type of white blood cell) in response to allergens, potentially improving the diagnosis of food and drug allergies
• Microarray technology: This allows for simultaneous testing of multiple allergens using a small amount of blood, potentially increasing efficiency and reducing costs
• Epigenetic testing: Researchers are exploring how epigenetic markers may predict the development of allergies and guide personalized treatment strategies

While these methods show promise, further research is needed to validate their clinical utility and establish standardized protocols.

Allergy testing is a complex but essential component of allergy diagnosis and management. By combining accurate testing methods with expert interpretation, allergists can develop tailored treatment plans that significantly improve the quality of life for allergy sufferers. As research continues to advance our understanding of allergies and testing methods, patients can look forward to even more precise and personalized approaches to allergy care in the future.

Testing and Diagnosis – Find An Allergist Today

Allergy Testing

Adults and children of any age can be tested for allergies. As soon as your first consultation, you can get tested. Once the results are in and the diagnosis is done, your allergist can sit down with you and tell you what you’re allergic to and, even better, what you can do about it. 

Your allergist may want to do skin testing, blood testing, or both. Any kind of allergy test is best done under the guidance of an allergist. These specialists are trained in the best methods for diagnosing and treating allergies.

Both blood and skin allergy tests can detect a patient’s sensitivity to common inhalants like pollen and dust mites or to medicines, certain foods, latex, venom, or other substances. Skin testing is the preferred method used by trained allergists, and is usually the most accurate. Blood tests may be ordered in specific situations.

It’s important to choose the right test, the one best able to aid the diagnostic process. For many reasons, that’s not an easy job. Allergy patients are often sensitized to many allergens, but are only clinically allergic to one or more specific substances. Allergists are trained to select tests that pinpoint the allergens which are actually causing the symptoms. 

These skills are important because there are many variables that can affect allergy test results. Correctly identifying a person’s specific allergic triggers helps an allergist develop the best therapies and management plans for each patient.

Board-certified allergists are specialists trained to help you take control of your allergies and asthma, so you can live the life you want. These specialists recognize that not all allergy tests are alike. They regularly review the scientific literature to learn which testing systems work better than others and how laboratory practices may affect test results.

Allergy tests should not be ordered randomly, either. They are chosen based on symptoms, environmental and occupational exposures, age, and even hobbies. All results are then interpreted in the context of the patient’s medical history.

Tests can be done for common allergens such as plant pollens, molds, dust mites, animal dander, insect stings and various foods such as peanuts, eggs, wheat, shellfish and milk. Testing also is available for some medicines, such as penicillin.

Types of Allergy Tests

Skin Testing

Allergy skin testing is the gold standard and is used along with the medical history to find out exactly what things a person is allergic to. 

Some medicines can interfere with skin testing, so you should let your allergist know about any medications you’re taking.

Skin tests are done in an allergist’s office. Skin tests give fast result and usually cost less than allergy blood tests. 

However, while testing may seem simple, it must be carried out by trained practitioners with an understanding of the variables and risks of the testing procedure. The skill of the tester can also affect the accuracy of the results.

Steps should include:

• After reviewing the patient’s medical history and performing a physical exam, the allergist determines that allergy skin testing is both appropriate and safe to perform on you that day.
• A trained staff member performs the skin testing under the supervision of the allergist.
• The skin test is read and graded for the level of response.

There are two types of skin tests:

• Prick or scratch test: In this test, a tiny drop of a possible allergen—something you are allergic to— is pricked or scratched into the skin. (This is also called a percutaneous test.) It is the most common type of skin test.
• Intradermal test: This test shows whether someone is allergic to things such as insect stings and penicillin. A small amount of the possible allergen is injected under the skin through a thin needle.

Skin tests for allergic disorders have been used successfully for more than 100 years. Today, prick or scratch tests are the most commonly-used type of skin test. These tests are not very invasive and, for most allergens, they tend to produce quick results. If the results of prick or scratch tests are negative, they may be followed by intradermal tests, which give allergists more details about what’s causing the symptoms.

Allergy symptoms might occur during the test. The most common symptoms are itching and swelling of the skin. In rare cases, a more serious reaction can occur, so skin testing should always be done by a specialist.

Blood Testing

Blood testing involves a single needle prick, and medicine does not interfere with the results. However, it takes a long time to get the results, and depending on the test, there can be false positives. Blood tests cost more than skin tests. There are many types of allergy blood tests, and some are more helpful than others.

The risk with allergy blood tests is pain or bleeding at the needle mark. Also, a few people may faint during blood testing.

Allergy Diagnosis

Blood test and skin test results alone do not diagnose allergies. All test results, from either type of test, must be interpreted together with your medical history.

When it comes to human allergic disease, an individual’s medical history is as important as the results of an allergy test. Medical history is the critical link between allergy test results and allergic disease itself. It tells the allergist valuable information about your health overall, your experiences with possible allergens, your symptoms at various times of the year, etc. 

If the results of skin and blood allergy tests are not clear or are inconsistent with the patient’s medical history, allergists rely on their training and experience along with a patient’s medical history and a physical examination—not test results—to make the final diagnosis.

Diagnosing Food Allergies | Symptoms &Treatment

Your First Appointment

Your first step toward relief is to schedule an appointment with an allergist to receive a proper diagnosis. Your allergist will evaluate several things before making an allergy diagnosis, and it’s nice to know what to expect.

Your allergist will begin by taking a detailed medical history. They will ask detailed questions about your history of allergy symptoms, your diet, your family’s medical history, and your home and living area. Some questions your allergist may ask include:

• The symptoms you have after eating the food.
• How long after eating the food these symptoms occurred.
• How much of the food you had.
• How often the reaction has occurred.
• Whether it occurs with other foods.
• Whether it occurs every time you eat the food.
• What type of medical treatment, if any, you received after having symptoms.

These questions help your allergist find out what is causing your allergy or making your symptoms worse. For example, allergy to pollen in the air, such as ragweed pollen, can be the cause of the swelling or itching in your mouth and throat if you eat certain foods like melons.

Your allergist may recommend allergy tests, such as a skin test or blood test to determine if you have a food allergy. A sensitivity to a food can be indicated in a skin prick test or a blood test, but does not always show a true allergy unless there has been a previous reaction to the food. These tests may offer clues about the causes of symptoms, but they cannot determine whether someone has a food allergy with absolute certainty. If necessary, an oral food challenge may be used to positively confirm the food that is causing the problem.

When a food allergy is suspected, it’s critically important to consult an allergist, who can decide which food allergy tests to perform, determine if food allergy exists, and counsel you on food allergy management once the diagnosis has been made.

Elimination Diet

Your allergist may narrow the search for foods causing allergies by placing you on a special diet. You may be asked to keep a daily food diary. The diary lists all food you eat and medication you take, along with your symptoms for the day.

If only one or two foods seem to cause allergies, you may try avoiding them. In this diet, you do not eat the suspect food at all for one to two weeks. If the allergic symptoms decrease during that period and flare up when you eat the food again, it is very likely the food causing your allergy.

However, which food you should avoid (and for how long) and when you should eat the food again (if ever) should be decided together with your allergist. You should never try to eat even a small quantity of any food your allergist has determined may cause a risk of anaphylaxis.

Your allergist may want to confirm these diet tests with a challenge test. Food allergy testing is a very important step in diagnosing food allergies.

Food Allergy Testing

 If done correctly and interpreted by a board-certified allergist, skin tests or blood tests are reliable and can rule food allergy in or out.

Your allergist will interpret the test results and use them to aid in a diagnosis. While both kinds of testing can signal a food allergy, neither is conclusive. A positive test result to a specific food does not always indicate that a patient will react to that food when it’s eaten. A negative test is more helpful to rule out a food allergy. Neither test can predict how severely a patient will react if they eat a specific food. Some people test “allergic” to a food (by skin or blood testing) and yet have no symptoms when they eat that food.

Skin Testing

Skin prick tests are conducted in a doctor’s office and provide results within 15-30 minutes. A nurse or the allergist administers these tests on the patient’s arm or back by pricking the skin with a small, sterile probe that contains a tiny amount of the food allergen. The tests, which are not painful but can be uncomfortable (mostly itchy), are considered positive if a wheal (resembling a mosquito bite bump) develops at the site.

The size of a wheal does not necessarily predict how severe your reaction might be if you eat that food.

Blood Testing

Blood tests, which are less sensitive than skin prick tests, measure the amount of IgE Bacteria, viruses and other microorganisms commonly contain many antigens, as do pollens, dust mites, molds, foods, and other substances. Although many types of antibodies are protective, inappropriate or excessive formation of antibodies may lead to illness. When the body forms a type of antibody called IgE (immunoglobulin E), allergic rhinitis, asthma or eczema may result when the patient is again exposed to the substance which caused IgE antibody formation (allergen).</span>” rel=”tooltip”>antibody to the specific food(s) being tested. Results are typically available in about one to two weeks and are reported as a number.

The level of IgE antibodies found for a specific food does not necessarily predict how severe your reaction will be if you eat that food.

Oral Food Challenge

To confirm your test results, your allergist may recommend an oral food challenge, which is the gold standard for food allergy diagnosis. However, the procedure can be costly, time-consuming, and in some cases is potentially dangerous, so it is not routinely performed.

During an oral food challenge, the patient is fed gradually increasing amounts of the suspected allergy-causing food over a period of time under strict supervision by an allergist. Emergency medication and emergency equipment must be on hand during this procedure.

Oral food challenges may also be performed to determine if a patient has outgrown a food allergy.

Food Allergy Diagnosis

Diagnosing food allergies can be complicated. Symptoms of food allergy can vary from person to person, and a single individual may not always experience the same symptoms during every reaction. Food allergic reactions can affect the skin, respiratory tract, gastrointestinal tract, and/or cardiovascular system, and people may develop food allergies at different ages.

Your allergist will look at both your test results and your medical history to make a food allergy diagnosis. 

If you are diagnosed with food allergies, your allergist will prescribe an epinephrine auto-injector and teach you how to use it.

You’ll need to be careful to avoid eating foods you are allergic to. Ask your allergist what safety precautions you need to take.

Basic principles for the diagnosis of allergic diseases – MEDSI

Allergy is a disease that manifests itself in the form of an acute sensitivity of the human body to various allergen substances upon contact with them.

To develop an effective treatment program, it is necessary to identify the causes of the disease, as well as the list of substances that cause the reaction. As in the case of other ailments, in order to achieve the maximum result of therapy, the diagnosis and treatment of allergic diseases must be carried out at an early stage.

Most significant allergy symptoms

Seek medical attention if the following symptoms appear:

• Skin rashes and itching
• Difficulty breathing (including deterioration of respiratory function before sleep)
• Chronic coryza, persistent sneezing, itchy nose
• Edema of different localization
• Redness and itching of the eyes, profuse lachrymation
• Bronchial asthma

These signs manifest themselves differently in each specific case, since an allergic reaction can occur to different groups of allergen substances:

• Food (fruits, dairy products, etc. ) (food form of allergy)
• Dust, pollen, wool (respiratory form)
• Some constituents of cosmetics and perfumes, plants, etc. on tactile contact (dermal form)

Also, the reaction may occur due to prolonged exposure to the sun and other reasons.

Main types of allergotests

Various types of allergotests are used to diagnose allergic diseases:

• Group of in vivo tests – carried out with the direct participation of the patient:
• Conjunctival examination (preparation is placed between the eyeball and eyelid)
• Skin tests (a scratch or small puncture is made on the skin through which the allergen is injected)
• Sublingual test (drug is inserted under the tongue)
• Nasal mucosal samples (allergen is injected into the mucosa)
• Group of in vitro tests – laboratory tests:
• Blood test for specific immunoglobulins E – ELISA (enzymatic immunoassay)

When analyzing reactions of the skin, mucous membranes, etc. , the appearance of an allergic reaction and its further course are monitored. In this case, the patient may experience discomfort.

In addition to allergy tests, the following types of examinations are used to diagnose the disease:

• Physical examination of the patient, interview and history taking
• Instrumental inspection
• Spirometer analysis with bronchodilation test to detect bronchospasm
• Measurement of various physical parameters (temperature, pressure, etc.)

Food Allergy Diagnosis

Food allergy testing uses a questionnaire, anamnesis, and various tests and trials.

To determine this type of allergy, the following manipulations are performed:

• The patient keeps a food diary in which he records the nature of the food, the time of intake, as well as the manifestation of any reactions of the body
• For two weeks he follows a doctor-specified diet that eliminates potential allergens
• After a period of corrective nutrition, the patient, under the supervision of doctors on an empty stomach, takes a capsule containing a potential allergen to which it is necessary to determine the reaction
• If there is no such reaction, the dose of the given allergen may be increased
• If the response to the maximum dose is not monitored, the test product is no longer considered an allergen
• In parallel, radioallergy and enzyme immunoassays are performed
• The diagnosis is confirmed if the patient’s condition returns to normal after a hypoallergenic diet

Diagnosis of drug allergy

When a reaction to drugs is detected, the doctor receives information not only from the patient himself, but also from his relatives, who may notice a deterioration in the patient’s condition after taking the medication.

At the same time, an ELISA blood test is performed to determine the concentration of antibodies indicating the presence or absence of an allergy.

It is important to remember that an allergic reaction to a particular drug may differ even in the same person: one day it may manifest itself in the form of urticaria and itching, and another time in the form of Quincke’s edema. Also, an allergy to medications can be hereditary and manifest itself in a number of family members.

Diagnosis of allergic diseases in children

Children’s immunity is not fully formed, so some methods of diagnosing allergies are not applied to children. So, skin tests are used only in cases where it is necessary to confirm a reaction to vaccines, food, or seasonal allergies.

The main methods for diagnosing allergies in a child are a survey and history taking, as well as laboratory blood tests for antibody concentrations. But it should be remembered that the signs of allergy as a result of such studies will only appear if the child has already encountered one of the allergens, even if he has a genetic predisposition to this type of allergy.

Reading and interpretation of tests and tests

Allergy test results should normally be:

A qualified allergist will interpret the results of all tests and prescribe the best treatment.

Advantages of the procedure at MEDSI

• Allergic diseases are diagnosed at MEDSI by immunologists-allergists of high qualification categories
• The network of clinics has its own research laboratories that allow manipulations in CITO mode
• 4 types of specially designed allergen panels are used for examining children
• MEDSI doctors use a comprehensive approach to treat allergies, which includes: reduction or complete cessation of contact with the allergen, drug therapy that suppresses symptoms, allergen-specific immunotherapy (ASIT)

To make an appointment with an allergist-immunologist, call 8 (495) 7-800-500.

Do not delay treatment, see a doctor now:

• Allergist-immunologist appointment
• Consultation of a pediatric allergist
• Treatment of food allergies in children

Allergy diagnostics

The danger of allergic diseases is that, if left untreated, the so-called “atopic march” occurs, that is, the progression of the disease (after atopic dermatitis, allergic rhinitis and then bronchial asthma may occur), which in turn will affect the quality of life of the patient.

Diagnosis of allergic diseases

The basis for adequate treatment of any disease is timely diagnosis.

In our center, we can offer you the opportunity to diagnose allergic diseases by taking blood tests for general and specific Ig E, performing PRIC tests (skin tests with allergens). The possibility of using this or that method is considered by the doctor after talking with the patient, collecting an anamnesis of the disease, taking into account the data of an objective examination.

For reliable results, preparation is necessary: ​​the abolition of certain groups of drugs, and so on. Setting up PRIC tests, like any other invasive intervention, has its contraindications, while at the same time, under certain conditions, this method has its advantages.

Often, allergic diseases (especially skin manifestations) are closely related to the pathology of the gastrointestinal tract, and full treatment is possible only after performing a certain additional examination, if necessary, consulting a gastroenterologist.

Allergology Clinic

In any case, for the timely and most complete diagnosis of the disease, you must consult a doctor, do not self-medicate. Otherwise, the path to health will be longer and more laborious. The allergology clinic at the FGBU “Consulting and Diagnostic Center with a polyclinic will offer you an individual approach, reasonable prices and high-quality treatment of various types of allergic diseases.