What kind of testing is best?

Posted on: Fri, 02/02/2001 - 12:35pm
AmyR's picture
Joined: 09/26/2000 - 09:00

pMy son has an appointment with the allergist on Monday. He has been one other time, two years ago. At that time, the allergist said he was too young (had just turned one) for skin testing and therefore he had a blood test to confirm he was PA. Now I'm wondering if I'm given a choice of how to re-test him, what should I say? I believe there are three possible tests: blood test, cap rast or rast. What test do people feel is the most reliable and what test tells you the sensitivity level? When my daughter was tested this past week and showed a positive reaction to dust mites, I asked how sensitive she was. The nurse said the test doesn't give a sensitivity level. Is environmental testing read differently? I would like to understand what level my son is. When he had his initial blood test, he was a level III. So now I'm wondering what test I should try to get for my son this time. Also, how often have people had their PA child re-tested?/p

Posted on: Fri, 02/02/2001 - 1:08pm
tkiaml's picture
Joined: 06/18/2000 - 09:00

Hi! I've heard skin prick is best and I've heard blood test is best! My son has had the skin prick test three times over the last year and a half and every time it comes out the same. Allergic to wheat, egg, dairy, nuts/peanuts, and now add mild reaction to dust mites, mold and cats. This seems to be very accurate based on reactions. The only one I have never given him is peanut/nut. I know for sure he is allergic to wheat, egg and dairy! His sister I know for sure is allergic to peanuts, tree nuts, and cats and this was confirmed by her skin prick test.
So in my kids case the skin test proved very reliable! They have not had blood tests though. In my understanding, levels don't really mean a whole lot-a 2+ can be just as severe a reaction as a 4+. My son's lowest range was 2+ to wheat and he had an anaphylactic reaction to it! With milk (4+) he had one sip and immediately vomited, started mild wheezing and some scattered hives.
Does this make sense to you? I hope I'm getting my point across. I'm sure you can do a search for more on allergy testing.
Take care!

Posted on: Fri, 02/02/2001 - 1:16pm
California Mom's picture
Joined: 07/14/2000 - 09:00

My understanding is that no test can tell you how severe a future reaction might be. Even when they provide you with a level, it doesn't necessarily mean anything. I think that the CAP RAST is the most sensitive blood test, and probably the most accurate. I don't know if it's any better than a skin test, though. My daughter's allergist, whom I really trust, has never tested her for peanuts or nuts. She doesn't think there's any point since she has obviously reacted to them. She told me that she does want to test her when she is 15. (Not sure why, but maybe she thinks there's a possibility she could outgrow it.) Good luck! Miriam

Posted on: Sat, 02/03/2001 - 1:04am
Dana's picture
Joined: 12/26/1999 - 09:00

My son is three years old now and was diagnosed PA at just over one year old after a severe reaction. His allergist did a blood test and said he was a level four, telling me this means he is very allergic.
His allergist said to avoid all nuts. My question is, can he be tested for individual nuts beyond peanuts, such as walnuts, pecans etc. and is there not a risk involved in doing a skin prick test to re-test for an allergy? Hoping someone can explain this.
Thanks for the help.
Oakley's Mom

Posted on: Sat, 02/03/2001 - 2:33am
rilira's picture
Joined: 11/11/1999 - 09:00

You can be test for nuts individually.My allergist blood tested my daughter for tree nuts ( at the time she was not allergic to peanuts). Since she has reacted to peanuts and the allergist will not test her. He said it is obvious she is allergic by her reactions. He said due to the severity of her past reactions ( to tiny amounts) he would never recommend a skin test. He said he would bet money a skin test would send her into a anaphylactic reaction.

Posted on: Sat, 02/03/2001 - 2:57am
PattyR's picture
Joined: 04/12/2002 - 09:00

My son had an anaphylactic reaction to a skin test just last year. I was concerned so the Dr. diluted the peanut protein with 100 parts water. He still reacted with throat tightening and needed to receive a shot of epinephrine and benadryl. It was very unsettling to say the least. I won't ever subject him to a skin test again.

Posted on: Sat, 02/03/2001 - 3:11am
maddiesmom's picture
Joined: 12/20/1999 - 09:00

My daughter was first tested at age 18 months after an exposure to peanuts and a reaction. She was given a CAP RAST and tested for ALL foods. She came up allergic to wheat, soy, milk, peas, eggs, peanuts and tree nuts. After those blood results came back, we went back into the office that next week and did a skin test for all of those foods that came up on the RAST to double check the accuracy . And, they were correct. Then at age 2 we went back and had her skin tested for all 60 foods because she was having strange hive reactions and I couldn't figure out if we missed something. She was pricked 60 times (and she didn't even cry-a brave little girl) and she came up allergic to soy, peanuts, tree nuts, peas, and cod fish. Then we, once again, had a CAP RAST done to double check. It came back that she was still allergic to soy, peanuts, tree nuts and peas (with the same numbers that were at her 18month test) but that she wasn't allergic to cod fish. We still avoid cod fish just to be safe. Both tests have been very accurate for us and she has not had any unknown culprits since. We are happy that we did BOTH tests to make sure we wearn't missing anything.

Posted on: Sat, 02/03/2001 - 12:38pm
Merri - Kim's picture
Joined: 01/31/2001 - 09:00

Our allergist doesn't do a blood test of any sort. He only does a skin test. I asked about a blood test and he said "Why - we know he's allergic" My doctor doesn't have the best bedside manor, but he is said to be (one of) the best in Canada. I don't know!

Posted on: Sun, 02/04/2001 - 9:05am
supermom1023's picture
Joined: 01/12/2001 - 09:00

My daughter is pa but my son is not. He is allergic to grass,trees and 1 mold. I had him rast tested for food allergies. The # by peanut was about 1-2. He has always eaten anything peanut with no problem. He still eats peanuts away from home. The nurse told me that rast testing was not as accurate as skin test. I had heard just the opposite. Also, what is the difference between a regular rast and a cap rast?

Posted on: Sun, 02/04/2001 - 1:37pm
Chris PeanutAllergy Com's picture
Joined: 04/25/2001 - 09:00

Merri - Kim
Please contact me when you have a few minutes(it is not related to this thread)
phone (207) 766-5292 (eastern standard time)
Stay Safe,

Posted on: Mon, 02/05/2001 - 10:37am
AmyR's picture
Joined: 09/26/2000 - 09:00

Thanks for all the input. As it turns out, my son was not tested today. His allergist feels that it is so rare to outgrow PA and there is no evidence that once sometime tests negative that they stay that way. He actually said I should weight 10-20 years to have him re-tested. I couldn't believe that. I thought it was more like 2-5 years. He also didn't want to test for tree nuts (he was negative two years ago at age 1) and feels that I should just tell everyone he is PA and TNA. It is much safer that way. The doctor assisting him even went so far as to say it would be a good idea to have both on his medic alert bracelet.

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