How is allergy testing done for kids?

Allergy testing for kids is usually a skin prick test, where an allergist places tiny drops of possible allergens on the forearm or back and lightly scratches the skin under each one, then checks for raised, itchy bumps after about 15 minutes; or a blood test that measures allergy antibodies (IgE) to specific foods or substances. KidsHealth's allergy testing guide notes that a positive test only means a person might be allergic (Allergy Testing, accessed November 12, 2026).

When testing makes sense

Testing helps when there's a pattern pointing to an allergy:

• hives, swelling or vomiting soon after eating a certain food;
• constant sneezing, itchy eyes or stuffy nose in certain seasons or around pets;
• eczema that's hard to control, especially in babies;
• a reaction to a sting;
• asthma with possible triggers.

Testing for lots of foods "just in case," with no history of reactions, isn't recommended. It can turn up positives that don't mean a true allergy and lead to cutting foods a child eats fine.

The skin prick test

What happens:

1. The nurse cleans the forearm or upper back and marks a grid with a pen.
2. A drop of each allergen goes beside a mark, plus two control drops: histamine (should bump) and saline (shouldn't).
3. A tiny plastic pick presses through each drop into the top layer of skin. No needles go deep, and there's no bleeding.
4. Your child waits about 15 minutes. Itchy, mosquito-bite-like bumps mean a reaction; the nurse measures them.
5. The skin is wiped clean. Itching fades within an hour or so.

How it feels: like a light poke or a pencil tip, then itchy. Most kids say the waiting and the itching are the hard part.

The blood test

A small blood draw measures IgE antibodies to specific allergens. If there are IgE antibodies to a food, it means the person might be allergic to it. Results take a few days. For tips on the needle part, see our guide to preparing a child for a blood test.

How to prepare your child

• Medicines. Ask the allergist whether any medicines should be paused. Don't stop asthma controllers or prescribed medicine without asking.
• Clothing. A short-sleeve shirt, or one that's easy to lift for back testing.
• Comfort. A tablet, book or favorite toy for the wait. The 15 minutes go slowly when you're itchy.
• What to say. "The nurse will put little drops on your arm and press them with a tiny tool. It might feel like a light poke and then get itchy. Then we wait and watch. I'll be right there." Avoid promising "it won't hurt"; say what it feels like.
• Hands off. Practice keeping hands still. Let them hold your hand or a squishy toy instead of scratching.

Reading the results

• Negative: usually means no allergy to that item.
• Positive: means your child's immune system makes antibodies to it, called sensitization. Many sensitized children eat the food with no problem. The size of the bump or the level in the blood helps, but doesn't decide alone.

That's why the allergist puts the results together with your child's history. A child who eats peanut butter every day without trouble and tests positive probably isn't allergic in a meaningful way.

The oral food challenge

When the answer is unclear, the allergist may suggest an oral food challenge: in the office, your child eats tiny, gradually larger amounts of the food while staff watch for a reaction for a few hours. It's the most accurate way to know, and staff are ready to treat any reaction right away. Bring snacks, books and patience.

After testing

If an allergy is confirmed, you'll get a plan: which foods to avoid, how to read labels, what a reaction looks like, and, for some allergies, a prescription for epinephrine auto-injectors with training. KidsHealth's hives page explains how skin reactions can be one sign of an allergy, and when they need urgent care (Hives, accessed November 12, 2026).

Ask about retesting over time. Many children outgrow allergies to milk and egg.

Helping a nervous child

Kids often do better when they know the order of things. Draw the steps on paper: car, waiting room, drops, poke, wait, wipe, sticker. Bring it with you and check each off.

For kids whose year includes allergy tests and new rules, a personalized book about doctor visits can walk them through it with themselves in the pictures. See the hospital book.

Questions to ask the allergist

Bring a short list so nothing gets forgotten in the room:

• Which test are you doing, and why that one?
• Does my child need to stop any medicine first, and for how long?
• What does a positive result mean for what my child eats or touches?
• Do we need an epinephrine auto-injector, and who should have one?
• Should we try an oral food challenge, and when?
• When should we test again? Some children outgrow milk and egg allergies.

Write the answers down or ask for a written plan. If your child goes to daycare or school, ask for an allergy action plan you can share with teachers.

Related reading

• Living with a food allergy and an EpiPen
• Getting a shot at the doctor

FAQ

Is the blood test as good as the skin test?

They're similar in accuracy for most uses; your allergist picks based on your child.

Does a big bump mean a severe allergy?

Not always. Bump size doesn't reliably predict how severe a reaction will be.