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Allergen-specific IgE antibody test

Related Terms

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Background

  • An allergen-specific immunoglobulin E (IgE) test, commonly often referred to as radioallergosorbent test (RAST®) is a type of blood test that can help determine if a patient who experiences allergy symptoms, such as runny nose, watery eyes and hives, is allergic to particular substances called allergens.
  • The in vitro test (performed outside of the body, in a laboratory setting) exposes a blood sample to suspected allergens (like dust mites, pollen or animal dander) to determine whether the patient has developed allergen-specific immunoglobulin E (IgE) antibodies. Antibodies are proteins that recognize and bind to specific antigens (foreign substances in the body).
  • The test is used to diagnose Type I allergic reactions. Type I allergic reactions involve IgE, which is specific for a particular drug, antigen or other allergen that triggers the allergic reaction. The allergen binds to the immunoglobulin on specific immune cells known as basophils and mast cells. This binding results in the release of chemicals that cause inflammation in the body within 30 minutes of exposure to the allergen. Inflammatory chemicals including histamine, serotonin, proteases, bradykinin generating factor, chemotactic factors (molecules that stimulate the immune response), leukotrienes, prostaglandins and thromboxanes are released. These chemical mediators cause symptoms associated with allergies such as hives, runny nose, watery eyes, sneezing, wheezing or itching. Type I allergic reactions are often triggered by food (like peanuts, shellfish and milk), drugs (like penicillin), inhaled allergens (like dust, pollen and pet dander), latex and insect venom (bees, wasps, etc.).
  • The test may also be conducted to monitor immunotherapy (allergy shots) or to determine whether an individual has outgrown an allergy.
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History

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How It Is Performed

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Test Results

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Risks

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Author Information

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References

Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

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The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.