Negative RAST & Positive SPT

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Hello all,

I'm new here. I'm glad that I found this site. My son Alex is 8 month old.

He had RAST test when he was about 4 month old due to his eczema, and the result showed that he is allergic to Egg and Wheat, but peanut is negative.

He had SPT when he was 7 month old, and the result for peanut is 5/26, which is quite high.

I'm a very confused by the two results. Does anyone have different RAST and SPT results like these! Thanks!

On Dec 10, 2007

Hi sorry and welcome,

So two things come to mind. One is some think that you have to be exposed once for the tests to be acurate. Personally I don't agree because there are people who have totally avoided something - IE the mom is allergic to Peanut and the kid still tests positive. The second is that new allergies can develop over time. If it were me I would wait until the next time you would regularly do a Rast and retest peanut. My son was positive both to Rast and SPT - he did have one known exposure before testing.

On Dec 11, 2007

Thanks for the reply!

My son's first reaction was to pears when he was 5 month old. I fed him a few teaspoon of Gerber baby food pears, and he reacted to it almost immediately. That was a mistake. I shouldn't feed him solid so early with knowing that he is allergic baby. He is my first baby, and I knew very little about food allergy at that time. Since the RAST result shows that he is only allergic to egg and wheat, I thought he can eat anything else. Fortunately he just got hives, no breathing problem.

his second reaction was to Johnson & Johnson baby oil when he was 6 month old. I massaged the baby oil to his skin and hoped it will cure the eczema. His skin turned red at the beginning, and about half hour later the hives developed over the whole body. He was screaming, and I can feel that his skin was burning. I gave he a bath (without soap) immediately, and he calmed down and fell sleep, but the hives didn't totally disappear until one hour later.

After these two reactions, I started take his allergies seriously, and started searching for information online. The SPT taken when he was 7 month old showed that he is also allergic to egg, peanut, oat, barley, dog, cat, dust mite and hamster. I was really scared when I saw peanut on the list.

On Dec 11, 2007

Hi and Welcome!! Yes, my dd (now 3 1/2 yo) was diagnosed just over a year ago and she was positive on blood test for egg, wheat and milk. SPT showed egg, no milk or wheat but also pos for peanut. We have kept her away from peanut ever since. However, this past August she had testing again, SPT was neg for peanut but pos for shellfish, almonds and cashews along with egg. So, we still avoid all Tree nuts, peanuts and shellfish and fish along with egg. She is also allergic to pork.

It was explained to us that whe may have a peanut allergy that she is in the process of outgrowing. It is very gray area and the recommendation from her allergist is because of her reactive history to other things on her "list", to definatly avoid peanuts too to be safe.

I don't know if that helps you or not, but I do wish you the best. My 5 yo dd also suffer from eczema and she is very sensitive to products with petrolatum that is high on the ingredient list. That's alot of things. She also has had the full body hives from these things.

Best wishes to you in this journey.

It is indeed overwhlming and scary. It's good to ask lots of questions!!

Kara

On Dec 13, 2007

Thanks KaraLH.

What's the wheal/ERY size of you son's positive result on peanut? Did he ever have peanut before the test?

On Dec 13, 2007

Actually it's my daughter and yes, she did have peanuts before. She about two weeks before we had her tested (before we knew she would was even going to be tested) She ate some peanuts with my dad at their house. Shortly after she started screaming and doubling over in pain holding her stomach. It lasted for over an hour. Then it passed when she fell asleep.

Fast forward to rast- neg for peanut. SPT 3+ was the number she got. At our allergist a 4+ is as high as they go. (Her egg was a 4++ plus some more!!)It was a rather large wheal. However, like I said, this past August she was tested again and was neg. But after that incident she had with the peanuts at my parents house, our allergist thinks perhaps she has one she is outgrowing. I don't really want to test his theory!

Hope this helps.

Kara

our new allergist shows results with the wheal/ery numbers our old one just gave a number 1-4 with a + or -.

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