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Allergy Blood Test: A Comprehensive Guide to Understanding Allergies and Testing

  • Post published:July 25, 2023
  • Post category:Blog

Allergies affect millions of people worldwide, causing various uncomfortable symptoms and impacting their quality of life. Identifying the specific allergens responsible for allergic reactions is crucial for effective management and treatment. One of the most reliable methods for diagnosing allergies is through an allergy blood test. In this article, we will delve into the details of allergy blood testing, its benefits, limitations, and how it helps in managing allergies.

What is an Allergy Blood Test?

An allergy blood test, also known as a specific IgE blood test or allergen-specific immunoglobulin E test, is a medical procedure used to determine an individual’s immune response to specific allergens. It measures the levels of immunoglobulin E (IgE) antibodies in the blood, which are produced by the immune system in response to allergens.

Where To Get Tested?

Say Goodbye To Waiting Rooms And Long Lines. Speedy Sticks offers at-home testing.

Types of Allergies Detected by Blood Tests

Allergy blood tests can identify various types of allergies, including:

Seasonal Allergies

Seasonal allergies, also known as hay fever or allergic rhinitis, occur during specific times of the year when certain plants release pollen into the air. Common allergens include tree pollen, grass pollen, and weed pollen.

Food Allergies

Food allergies can cause adverse reactions to certain foods, leading to symptoms such as:

  • hives
  • digestive issues or
  • anaphylaxis

Allergy blood tests can pinpoint food allergens like peanuts, eggs, milk, and shellfish.

Environmental Allergies

Environmental allergies are triggered by substances found in everyday environments, such as dust mites, mold spores, pet dander, and cockroach particles. These allergens can be identified through blood testing.

How Allergy Blood Tests Work

During an allergy blood test, a small sample of the patient’s blood is taken and sent to a laboratory for analysis. The blood sample is analyzed to measure the levels of specific IgE antibodies directed against particular allergens. The results provide valuable information about the substances that trigger an allergic response in the patient.

Benefits of Allergy Blood Testing

Allergy blood tests offer several advantages:

  1. Accuracy: Allergy blood tests have high levels of accuracy in detecting allergens and can identify both common and rare allergies.

  2. Comprehensive Results: The test can screen for numerous allergens in a single sample, providing a comprehensive profile of the patient’s sensitivities.

  3. Minimal Discomfort: The blood test involves a simple blood draw, which causes minimal discomfort and is generally well-tolerated by patients.

  4. No Allergen Exposure: Unlike skin prick tests, allergy blood tests do not expose patients to potential allergens, making them safer for individuals with severe allergies.

When to Consider an Allergy Blood Test

An allergy blood test may be recommended by a healthcare provider if:

  • The patient experiences recurrent allergy symptoms without a clear trigger.
  • The patient has a family history of allergies.
  • The patient is taking medications that may interfere with skin prick testing.
  • The patient has a skin condition that affects the accuracy of skin testing.

Preparing for an Allergy Blood Test

Before an allergy blood test, patients may need to avoid certain medications that could interfere with test results. It is essential to follow the allergist’s instructions carefully to ensure accurate and reliable outcomes.

Understanding Allergy Blood Test Results

The allergy blood test results typically include:

IgE Levels

The levels of specific IgE antibodies are measured, indicating the immune system’s sensitivity to particular allergens. Higher IgE levels suggest a stronger allergic response.

Specific Allergen Results

The test results will specify which allergens produced a reaction in the patient’s blood sample.

Severity of Allergic Reactions

The allergist will assess the severity of the patient’s allergic reactions based on the test results, helping to determine the appropriate management and treatment plan.

Comparing Allergy Blood Tests with Other Allergy Tests

Allergy blood tests have several advantages over other allergy testing methods, such as skin prick tests or patch tests. While skin tests provide immediate results, blood tests are often preferred for their comprehensive nature and safety.

Limitations of Allergy Blood Tests

Despite their accuracy, allergy blood tests have some limitations:

  • False Positives: The test may indicate sensitivity to an allergen, but the patient does not experience symptoms upon exposure.
  • False Negatives: In some cases, the test may not detect an allergy, even if the patient experiences symptoms in response to an allergen.

Addressing False Positives and False Negatives

To address false positives and false negatives, the allergist will carefully consider the patient’s medical history, symptoms, and other diagnostic test results. Additional testing or a trial elimination diet may be recommended for further confirmation.

Allergy Management and Treatment Options

Once allergens are identified, the allergist will work with the patient to develop an allergy management plan. This plan may include:

Allergen Avoidance

The primary approach to managing allergies involves avoiding exposure to known allergens. This may include dietary changes, environmental modifications, or lifestyle adjustments.


Allergy medications, such as antihistamines, decongestants, and nasal corticosteroids, can help relieve allergy symptoms.


For individuals with severe allergies, allergen immunotherapy (allergy shots) may be recommended to desensitize the immune system and reduce allergic reactions over time.

The Role of Allergy Blood Testing in Chronic Conditions

Allergy blood testing plays a crucial role in managing chronic allergic conditions, such as asthma and eczema. Identifying and avoiding allergens can significantly improve the quality of life for individuals with these conditions.

Can I Eat Before an Allergy Blood Test?

Yes, fasting is not necessary for allergy blood tests.

How Long Does It Take to Get Allergy Blood Test Results?

It usually takes a few days to a week to receive the results, depending on the testing facility.

Are Allergy Blood Tests Safe for Children?

Yes, allergy blood tests are safe for children of all ages.

Do Allergy Blood Tests Detect Delayed Allergies?

No, allergy blood tests primarily detect immediate allergic reactions.

Can Allergy Blood Testing Diagnose Food Intolerances?

No, allergy blood tests only identify IgE-mediated allergies, not food intolerances.


Allergy blood testing is a valuable tool in identifying specific allergens responsible for allergic reactions. Its accuracy and comprehensive nature make it an essential diagnostic method for managing allergies effectively. By knowing which substances trigger allergies, patients can take necessary precautions and receive appropriate treatment to lead a healthier and symptom-free life.

Say Goodbye To Waiting Rooms And Long Lines. Speedy Sticks offers at-home testing.