Table of ContentsView AllTable of ContentsDiagnosisSkin TestsBlood TestsSigns You Need a TestFrequently Asked Questions
Table of ContentsView All
View All
Table of Contents
Diagnosis
Skin Tests
Blood Tests
Signs You Need a Test
Frequently Asked Questions
Allergiesoccur when yourimmune systemoverreacts to a specific substance called anallergen, or trigger. Your immune system may identify the trigger—which is actually harmless—as a threat, and set the immune response into motion. There are several different methods of diagnosing allergies, includingblood testsandskin tests.
This article will cover how allergies are diagnosed with skin tests and blood tests, as well as the advantages and disadvantages of both.
Verywell / Danie Drankwalter
How Allergies Are Diagnosed
Your healthcare provider may suspect allergies based on yoursymptomsand health history or a physical examination.The test they choose to diagnose allergies often depends on what type of trigger they think may be responsible for your symptoms.
If you have been takingantihistaminesfor your symptoms, you will likely need to stop taking them for a period of time before you can be skin tested.
Allergy SymptomsSymptoms of allergies may include:Skin rashes such ashivesItching and rednessSneezingRunny noseSore throatItchy, watery eyesFood allergiesmay cause other symptoms such asnausea,diarrhea, or other stomach issues.
Allergy Symptoms
Symptoms of allergies may include:Skin rashes such ashivesItching and rednessSneezingRunny noseSore throatItchy, watery eyesFood allergiesmay cause other symptoms such asnausea,diarrhea, or other stomach issues.
Symptoms of allergies may include:
Food allergiesmay cause other symptoms such asnausea,diarrhea, or other stomach issues.
Skin Test for Allergies
Procedure
Skin tests for allergies include skin prick testing, intradermal testing, and skin patch testing.
Safety
Skin tests for allergies are generally considered safe. However, those who test positive may experience irritation at the site of the test (itching, hives, or slight pain from the scratch or needle stick).
While extremely rare, these tests could potentially cause an anaphylactic reaction in some people.
Anaphylaxisis a severe and life-threatening allergic reaction. Of the different types of skin testing, those that are performed in entirety at an office or clinic under the supervision of a healthcare provider are the safest, since those providers are trained to recognize andtreatanaphylaxis.
AnaphylaxisAnaphylaxis is a life-threatening allergic reaction that requires immediate emergency medical attention. Anaphylaxis can cause the throat to swell, which obstructs a person’s airways, making breathing difficult. For severe allergies, a person shouldcarry an injectable epinephrine device (EpiPen)at all times.
Anaphylaxis
Anaphylaxis is a life-threatening allergic reaction that requires immediate emergency medical attention. Anaphylaxis can cause the throat to swell, which obstructs a person’s airways, making breathing difficult. For severe allergies, a person shouldcarry an injectable epinephrine device (EpiPen)at all times.
Cost
Skin testing is among the most affordable of tests used to detect allergies. The exact cost will vary depending on the healthcare provider and the type of test used. Most health insurance plans will cover this type of testing.
Contact your healthcare provider and insurance company, if you have one, for details regarding pricing prior to receiving the test.
Accuracy
False negatives are very unlikely with skin testing for allergies. The quality of the allergen sometimes creates false negatives.
However, false positives occur about 50%-60% of the time with skin prick testing. For this reason your healthcare provider may order follow-up tests to confirm diagnosis.
Blood Tests for Allergies
Blood tests for allergies look for a certain type of antibody calledimmunoglobulinE (IgE), which the body produces once it becomes allergic to an identified trigger. This type of testing is also calledRASTor ImmunoCap testing.
Blood is drawn, typically using a needle and syringe, and then sent to a laboratory for analysis. The lab technician will add suspected allergens to the blood sample and see if IgE is produced in response to a specific allergen. Then IgE levels are measured.
Blood tests for allergies are extremely safe, with the only potential for any adverse reaction coming from the blood draw process (for example, pain or infection at the site of the needle stick).
This type of testing costs from $20 to over $200 (without insurance).The best way to determine your out-of-pocket cost is to contact your insurance provider (if you have one) or healthcare provider for pricing info before receiving the test.
Unfortunately, like skin testing, IgE testing also sees a high false positive rate at about 50%-60%.
Signs You Need an Allergy Test
It can be difficult toknow if you have allergies, especially if your symptoms are similar to thecommon cold. But a cold typically only lasts a few days or weeks at most, while allergies persist.
You may need an allergy test if you have symptoms of allergies, such as skin rashes, hives, sneezing, congestion,sinus problems, or an episode of anaphylaxis. You may have noticed that these symptoms coincide with exposure to certain triggers.
Review your symptoms and medical history with your healthcare provider to determine if you need an allergy test and which type of testing would be best for you.
The Best At-Home Allergy Tests for Quick, Reliable Results
Summary
Skin tests and blood tests are two primary testing methods to diagnose allergies. Allergy tests are generally considered safe and affordable. A healthcare provider who is uniquely qualified to order these types of tests will perform them and determine the results. You may require more than one type of allergy test to help confirm a diagnosis.
A Word From Verywell
Allergies are extremely common and can interfere with your quality of life. Undiagnosed and untreated allergies can lead to conditions such assinusitisandnasal polyps. Proper management of allergies depends on an accurate diagnosis, which can be achieved with the help of a qualified healthcare provider, such as anallergist.
The most common environmental allergies include pollen, dust, mold, cockroaches, and pet dander. The most common food allergies in the U.S. include milk, shellfish, nuts, soy, eggs, and wheat. Allergies to insect venom affect about 5% of the population.
Yes, the immune system changes often throughout your life, so it’s possible to both outgrow childhood allergies and to develop new allergies as an adult.
9 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Asthma and Allergy Foundation of America.Allergy diagnosis.MedlinePlus.Allergy testing - skin.Food and Drug Administration.FDA requires warning about anaphylaxis following false negative food allergen skin test results in the prescribing information for all allergenic extracts for diagnosis of food allergy.Food Allergy Research and Education.Skin prick tests.Quest.Allergy tests.PlushCare.Allergy treatment available online today.Food Allergy Research and Education.Blood tests.Asthma and Allergy Foundation of America.Allergy facts.National Health Service.Allergies.
9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Asthma and Allergy Foundation of America.Allergy diagnosis.MedlinePlus.Allergy testing - skin.Food and Drug Administration.FDA requires warning about anaphylaxis following false negative food allergen skin test results in the prescribing information for all allergenic extracts for diagnosis of food allergy.Food Allergy Research and Education.Skin prick tests.Quest.Allergy tests.PlushCare.Allergy treatment available online today.Food Allergy Research and Education.Blood tests.Asthma and Allergy Foundation of America.Allergy facts.National Health Service.Allergies.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Asthma and Allergy Foundation of America.Allergy diagnosis.MedlinePlus.Allergy testing - skin.Food and Drug Administration.FDA requires warning about anaphylaxis following false negative food allergen skin test results in the prescribing information for all allergenic extracts for diagnosis of food allergy.Food Allergy Research and Education.Skin prick tests.Quest.Allergy tests.PlushCare.Allergy treatment available online today.Food Allergy Research and Education.Blood tests.Asthma and Allergy Foundation of America.Allergy facts.National Health Service.Allergies.
Asthma and Allergy Foundation of America.Allergy diagnosis.
MedlinePlus.Allergy testing - skin.
Food and Drug Administration.FDA requires warning about anaphylaxis following false negative food allergen skin test results in the prescribing information for all allergenic extracts for diagnosis of food allergy.
Food Allergy Research and Education.Skin prick tests.
Quest.Allergy tests.
PlushCare.Allergy treatment available online today.
Food Allergy Research and Education.Blood tests.
Asthma and Allergy Foundation of America.Allergy facts.
National Health Service.Allergies.
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