Getting an allergy test typically starts with a visit to your primary care doctor or a direct appointment with an allergist, who will recommend the right type of test based on your symptoms. Most people end up with a skin prick test that takes about 20 to 30 minutes in the office, though blood tests, patch tests, and oral challenges are also options depending on what you’re reacting to. Here’s what to expect at each step.
Start With Your Doctor or Book Directly
You have two main routes. Your primary care doctor can evaluate your symptoms and refer you to an allergist, or in many cases you can schedule with an allergist directly, especially if your insurance plan doesn’t require a referral. If you’re not sure whether your symptoms are allergy-related, starting with your regular doctor makes sense. They can rule out other causes and point you toward the right specialist.
An allergist is a physician who completed training in either internal medicine or pediatrics, then spent an additional two years in allergy and immunology training and passed a board certification exam. You can verify board certification through the American Board of Allergy and Immunology. For straightforward cases like seasonal allergies, a single consultation is often enough to confirm a diagnosis, identify triggers, and get a treatment plan. More complex situations, like poorly controlled asthma or interest in allergy shots, may involve ongoing co-management between your allergist and primary doctor.
Types of Allergy Tests
Skin Prick Test
This is the most common allergy test. A skin prick test checks for immediate allergic reactions to as many as 50 substances at once, including pollen, mold, pet dander, dust mites, and foods. Small drops of allergen extracts are placed on your forearm or back, and your skin is lightly pricked through each drop. After about 15 minutes, the provider checks for raised, red bumps at each site. A bump indicates you’re producing an immune response to that allergen. The whole appointment, including the consultation, typically runs under an hour.
Intradermal Test
If a skin prick test is inconclusive, your allergist may inject a tiny amount of allergen just beneath the skin’s surface. This intradermal test is more sensitive and is commonly used to check for allergies to insect venom or penicillin. The injection site is examined after about 15 minutes. Intradermal testing carries a slightly higher risk of reaction than skin prick testing: roughly 55 systemic reactions per 100,000 tests when both methods are combined, compared to 30 per 100,000 for skin prick tests alone.
Blood Test
Blood tests measure the level of allergy-related antibodies (IgE) your immune system produces in response to specific allergens. They’re a good alternative if you can’t undergo skin testing, for instance if you have severe eczema covering your arms and back, or if you can’t stop taking antihistamines. A blood draw is sent to a lab, and results usually come back within a few days to a week. Blood tests are not used for penicillin allergy.
Patch Test
Patch testing is designed for contact dermatitis, the itchy rash you get from touching something you’re allergic to, like nickel, fragrances, or certain preservatives. No needles are involved. Allergens are applied to adhesive patches placed on your back. You wear the patches for two days, then return to have them removed and your skin checked. Two days after removal, you go back for a second reading. Providers often apply patches on a Monday, remove them Wednesday, and do the final check on Friday. This extended timeline is necessary because contact allergies produce delayed reactions that can take days to appear.
Oral Food Challenge
When skin and blood tests aren’t definitive for a suspected food allergy, your allergist may recommend an oral food challenge. You eat small, gradually increasing amounts of a food under medical supervision, and the provider watches for reactions over several hours. This is considered the gold standard for diagnosing food allergies, but it’s done in a clinical setting with emergency equipment on hand.
How to Prepare
The most important preparation step is stopping antihistamines at least five days before a skin test. This includes over-the-counter allergy pills like cetirizine, loratadine, and diphenhydramine, as well as any combination cold or sleep medications that contain antihistamines. These drugs suppress the skin’s immune response and can produce false negatives, making it look like you’re not allergic when you are.
Certain antidepressants and heartburn medications can also interfere with results. When you schedule your appointment, the office will give you a specific list of what to stop and when. Blood tests don’t require you to stop any medications, which is one reason allergists choose them for patients who can’t go without antihistamines. No fasting is needed for any type of allergy test.
Testing for Children
Skin prick testing can be done on children of almost any age. The only real lower limit is that it’s rarely performed on infants younger than 6 months. For very young children, blood tests are sometimes preferred simply because it’s easier to get a single blood draw than to keep a baby still while monitoring multiple skin prick sites. If your pediatrician suspects a food allergy in your infant or toddler, they’ll likely refer you to a pediatric allergist who can decide which approach makes sense given your child’s age and symptoms.
Safety During Testing
Allergy skin tests are very safe. A large study covering nearly 500,000 skin tests found an overall systemic reaction rate of just 33 per 100,000 tests. Systemic reactions are those that go beyond the test site, like hives on other parts of the body or, very rarely, a drop in blood pressure. The risk varies by what’s being tested: aeroallergens like pollen and dust had the lowest rate (15 to 23 per 100,000), while latex and antibiotic testing carried somewhat higher rates. Allergists’ offices are equipped to treat reactions immediately, which is why testing is done in a clinical setting rather than at home.
What It Costs
If you have insurance, allergy testing is generally covered when ordered by a physician, though you’ll want to check whether your plan requires a referral and what your copay or coinsurance looks like. Without insurance, here’s what to expect:
- Initial consultation: $100 to $250, often billed separately from the test itself
- Skin prick test: $60 to $300
- Blood test (IgE): $200 to $1,000, depending on how many allergens are included in the panel
- Patch test: $200 to $1,000
- Oral food challenge: $300 to $800
Follow-up visits to review results or adjust treatment typically run $50 to $200. Costs vary significantly by region and provider, so it’s worth calling ahead for a price estimate, especially if you’re paying out of pocket.
Skip the At-Home IgG Kits
You’ve probably seen at-home test kits marketed as food sensitivity panels. Most of these measure IgG antibodies to 90 or 100 foods and claim that high IgG levels indicate a sensitivity. The problem is that this has never been scientifically validated. IgG antibodies to food are a normal part of the immune response to eating. Higher levels of certain IgG subtypes are actually associated with tolerance to foods, not intolerance. Both the American Academy of Allergy, Asthma & Immunology and the Canadian Society of Allergy and Clinical Immunology recommend against using IgG testing to diagnose food allergies or sensitivities. These kits can lead you to unnecessarily eliminate foods from your diet based on meaningless results.
Legitimate at-home options do exist for collecting a blood sample that’s sent to a lab for standard IgE testing. These can be a reasonable starting point, but they still benefit from professional interpretation. A positive IgE result doesn’t always mean you’ll have a clinical reaction to that allergen, and a negative result doesn’t always rule one out. An allergist can put the numbers in context with your actual symptoms.