From the Guidelines
Skin prick tests and specific IgE blood tests are the most effective fast tests for identifying airborne allergens, with skin prick tests providing immediate results and specific IgE blood tests offering a useful alternative for patients with severe skin conditions or those taking medications that may interfere with skin test results. These tests can help identify allergies to common airborne allergens such as pollen, dust mites, pet dander, and mold, and are highly sensitive and specific for aeroallergens 1. The results of these tests should be interpreted by an allergist alongside the patient's medical history, as positive results do not always mean the patient will experience symptoms when exposed to that allergen.
Some key points to consider when choosing between skin prick tests and specific IgE blood tests include:
- Skin prick tests are generally more sensitive and provide immediate results, but may be affected by patient medications 1
- Specific IgE blood tests may be preferred for patients with severe skin conditions, those taking medications that could interfere with skin test results, or those who cannot stop taking antihistamines 1
- Both tests can help identify specific triggers and develop appropriate avoidance strategies or targeted treatment plans 1
- The use of standardized allergen extracts can increase the consistency of skin test results 1
It's also important to note that other tests, such as IgG or total IgE, are not recommended for identifying airborne allergens, as they do not yield information helpful for management of allergic rhinitis 1. Overall, skin prick tests and specific IgE blood tests are the most effective fast tests for identifying airborne allergens, and should be used in conjunction with a patient's medical history to develop an effective treatment plan.
From the Research
Fast Tests for Airborne Allergens
- The skin prick test (SPT) is a common test for diagnosing allergies, including those caused by airborne allergens, and can test multiple allergens in 15 to 20 minutes 2, 3.
- SPT is minimally invasive and has a good correlation with in vitro tests, making it a reliable and convenient option for diagnosing allergic diseases 2.
- The test can identify sensitivity to various allergens, including inhalants, and has a positive predictive value ranging from 95-100% 2.
- Other tests, such as ImmunoCAP and ISAC, can also be used to diagnose allergies, but SPT is often the preferred first-line test due to its ease of use and safety 3, 4.
- When choosing a test, it's essential to consider the type of allergy being diagnosed, as well as the patient's medical history and any previous reactions to tests 5.
Types of Tests
- Skin prick test (SPT): a fast and reliable test for diagnosing allergies, including those caused by airborne allergens 2, 3.
- ImmunoCAP: a laboratory test that measures serum allergen-specific IgE antibodies, often used to confirm diagnoses 4.
- ISAC: a multiplex assay that tests for specific IgE against multiple allergen components, useful for diagnosing complex allergies 4.
- Patch test: a test used to diagnose type IV hypersensitivity reactions, often used for skin allergies 5.
Considerations
- When interpreting test results, it's crucial to consider the patient's clinical history and any previous reactions to tests 2, 4.
- The choice of test depends on the specific allergy being diagnosed, as well as the patient's medical history and any previous reactions to tests 5.
- SPT is generally considered safe, but in vitro IgE tests may be preferred if the patient has a history of severe reactions 2.