Testing & Diagnosis

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.