Allergy Testing

Allergy tests help an allergist figure out what you are, and are not, allergic to. They work best when combined with your medical history and a physical exam (AAAAI). This guide explains the main types of allergy tests, what home test kits can and can’t tell you, and why some popular “food sensitivity” tests aren’t recommended.

Types of Allergy Tests

Skin prick (scratch) test

In a prick or scratch test, a tiny drop of a possible allergen is pricked or scratched into the skin. It is the most common type of skin test. You wait about 15 minutes to see whether a small red lump appears (ACAAI). Skin tests have been used for more than 100 years and are not very invasive (ACAAI).

Intradermal test

If prick tests are negative, an allergist may follow with an intradermal test, where a small amount of allergen is injected just under the skin. It is often used for insect stings and penicillin (ACAAI).

Blood (IgE) test

Blood tests measure allergy antibodies (IgE) and can be used when skin testing isn’t practical. Medicines don’t interfere with the results, but results take longer, blood tests cost more than skin tests, and some can give false positives (ACAAI).

Oral food challenge

For suspected food allergies, an oral food challenge is considered the most accurate way to make a diagnosis. You eat small, increasing amounts of the food under strict medical supervision. Because a severe reaction is possible, it should only be done by experienced allergists with emergency medicine on hand (ACAAI).

Food Allergy Testing: What a Positive Result Means

A positive skin or blood test does not, by itself, diagnose a food allergy. NIAID notes that food allergy testing confirms a diagnosis when you have a history of reactions to a food, that testing should only target the food you reacted to, and that broad panels of many foods should not be performed (NIAID). A negative test is useful for ruling an allergy out (ACAAI).

This matters for seafood too. Shellfish is one of the most common food allergens in adults (ACAAI). If you’ve reacted to shrimp, crab, lobster or fish, an allergist can test for the specific species involved (ACAAI).

IgG “Food Sensitivity” Tests: The Evidence Warning

IgG food panels are not a valid way to diagnose food allergies or food sensitivities. These tests, sold by many companies and often available at home, report IgG levels to 90 to 100 foods. The AAAAI says the test “has never been scientifically proven” to do what it claims. IgG is likely a normal immune response to eating a food, and higher IgG4 levels may simply be associated with tolerance (AAAAI).

Because of the lack of evidence, the AAAAI and the Canadian Society of Allergy and Clinical Immunology recommend against using IgG testing to diagnose food allergies or intolerances (AAAAI). Cutting out many foods based on these results can restrict your diet for no reason.

Food intolerances, like lactose intolerance, are real, but they are different from allergies. They cause digestive symptoms such as bloating, gas or diarrhea, and they are not dangerous the way an allergy can be. No single test can identify them (AAAAI).

Are Home Allergy Test Kits Worth It?

Home kits usually involve a finger-prick blood sample mailed to a lab. Some measure IgE, which is the same type of antibody allergists test for. Others measure IgG, which has no proven diagnostic value (AAAAI). Even a legitimate IgE result can’t diagnose an allergy without your history, since a positive test alone doesn’t make a diagnosis (NIAID). If you use a kit, check which antibody it measures and review the results with a doctor before changing your diet or medicines.

Where to Get an Allergy Test

Allergists are the experts who test for, diagnose and treat allergies (ACAAI). An allergist is a pediatrician or internist with at least two extra years of specialized training (AAAAI). Adults and children of any age can be tested, often at the first visit (ACAAI). Your primary care doctor can refer you or order some blood tests.

How to Prepare for Skin Testing

• Tell your allergist about every medicine you take, including over-the-counter products.
• Antihistamines usually need to be stopped 3 to 7 days before skin testing. Ask your allergist when to stop.
• Nasal steroid sprays and asthma medicines are generally fine to continue (ACAAI).

If your testing points to pollen, see our guides to pollen allergies and treatment options. For local pollen seasons, see the Florida pollen guide.

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Written by: SeasonalAllergies.org Editorial Team (October 17, 2026)

This article is for general education and is not medical advice. Talk with your doctor about your symptoms and before changing your diet or medicines based on a test result.

Allergy Testing FAQs

Are home allergy tests accurate?

It depends on what they measure. IgG panels aren’t a valid way to diagnose allergies or sensitivities (AAAAI), and even IgE results need a doctor to interpret them alongside your history (NIAID).

What is the most accurate food allergy test?

An oral food challenge done under medical supervision is considered the most accurate (ACAAI).

Do skin prick tests hurt?

They may hurt slightly, and a positive spot can itch. Results appear in about 15 minutes (ACAAI).

Should I stop antihistamines before an allergy test?

Usually, for 3 to 7 days before skin testing. Ask your allergist first (ACAAI).

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