How Accurate Are Allergy Skin Tests?

Updated on February 05, 2013
S.S. asks from Los Angeles, CA
5 answers

My son was tested for allergies via the skin test when he was about a year old and tested positive for dogs and negative for peanuts. Today he got tested again (a year later) and this time it was the opposite -- he tested negative for dogs and positive for peanuts. And yet, he broke out in a few hives after we got a 2nd dog and has been eating peanut butter with no adverse effects for months now. I'm wondering how accurate these skin tests are?? Anyone have any experience with these things being wrong?

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answers from Miami on

I was told by my allergist that allergies can pop up at anytime and also change. I am highly allergic to dust and mold. I was tested about two years ago. I never had allergies until I was pregnant with my second child. I would say they are accurate but keep in mind that if you are predisposed for allergies, then allergies for other things can pop up when you were in fact not allergic before. What does the doctor say about this reversal of allergies in your son??

1 mom found this helpful


answers from Los Angeles on

They are not super accurate. Unfortunately, no allergy testing is really foolproof. There can be false positives and false negatives. Makes it pretty hard to know what's going on.

It is also possible to develop allergies that you didn't have in the past and to outgrow allergies, so it is quite possible for test results to change from year to year.

Just keep your eye on him when he eats peanut butter. Even though he's been fine in the past, if there is some indication of a sensitivity/allergy, it IS possible that he will react with continued exposure.



answers from Tulsa on

My friend tested negative for something that caused her throat to swell shut.
The doctor didn't believe her even after the skin test. She ate some in front of him and it took 2 doses to get her throat to stop swelling. I tested negative for everything except a single tree, yet I have allergic reactions to several things.



answers from Pittsburgh on

Allergy testing can help but has not been very accurate in our family. i am highly allergic to dust and mold- after brief exposure my head becomes congested and i get a sore throat. Dust and mold, however, did not show positive in my skin testing this year. they did show positive every other time i have been tested in the past. i know i am allergic to tree pollens and ragweed. When i was young, tree pollens and weeds always tested positive , then they did not.. This time maple trees showed a reaction. My sister had the same experience. She knows she is highly allergic to mold and it showed no reaction on her skin tests. So the point is, i know for sure i am allergic to some things, yet sometimes they test positive and sometimes they don't. i should note i have had allergies since i was a child and am now 60 so i have gone through this several times.



answers from Atlanta on

We have been told several times by several specialists that skin tests are not reliable in young children. You could have a blood test done, but even this is not 100% reliable. Unfortunately, you just need to wait. This is why they suggest trying just a small amount of common allergen foods. This way, if there is even a small reaction, you'll know and be able to get the help necessary. As far as environmental allergens - my son (and I) have many allergies. I had a skin test done last year, and since we both have the same symptoms at the same times, we're basing our treatment on him having the same allergies as me until he is old enough to be tested. At the beginning of allergy season, we just start up the Zyrtec and keep a standing prescription of Orapred. Due to other health issues with DS, we also have multiple inhalers and a nebulizer. So sorry you have to deal with this - no fun!!!

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