skin testing

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My daughter has been diagnosed with a peanut allergy. She had a reaction when she shared her brother's (not pa)peanut butter sandwich at 10 months of age. She was then confirmed to have the allergy when she was skin tested at 15 months. They did the test on her forearm (a huge number of allergens seemed to be tested) and she showed up a 8X6mm weal with the peanut allergen. I was not offered a RAST or CAPRAST test for her (perhaps she's too young?). Reading the literature on the net and the discussion questions on this site has led me to question the accuracy of the test for future reference ie if she gets tested again and the weal is smaller or the same, does it mean anything? I may ask her allergist about the CAPRAST when I next see him (probably in a year's time to test her again) - am praying real hard that she is one of the 20% that outgrows it.

On May 11, 2002

Welcome to the boards Li-Lian!! Actually my daughter was RAST tested when she was 12 months, so she probably is not too young. I am also hoping my dd is one of the 20% who outgrow but we are living as if she will never outgrow because it is such a small chance. They are now even finding that some kids thought to have outgrown are having problems with the allergy reoccurring later in life. Not to be the bearer of bad news but just to let you know. Now this is only my opinion but I will not have my dd scratch tested again for quite a long time. I plan on having her CAP RAST tested yearly to keep an eye on her numbers but the scratch test is out. The reason why is that is considered an exposure and they say the key to outgrowing is absolutely no exposure at all for a couple of years. Maybe if she has a few years of negative RAST scores and they want to do a scratch test before a food challenge I would allow that but that is the only way. As far as your question of if she does get scratch tested and the wheals get smaller, the one thing I keep reading about this allergy is it's unpredictability! So the next reaction may be smaller but it really doesn't mean much. Just keep those hopes up! This board has helped me more than anything else! It keeps you informed and lets you know you have people who understand all your frustrations! We're all here for each other! Take care! [img][/img] kcmom

On May 12, 2002

thanks for the info kcmom and encouragement that came with it. I'm heading off to singapore in June and face it with fear and trepidation knowing full well that there will be countless opportunities where she will be exposed. sigh. we're heading back for my grand-dad's big 84th birthday and with the lack of knowledge about potentially fatal allergies in asia, it's hard to explain it to well-meaning friends and relatives. take my mother-in-law who thinks that it's just a rash producing allergy so it doesn't matter that the soup contains peanuts, you can just drink the soup and not eat the peanuts...I can't get the message across and can't hope to...I will ask the allergist about RAST and CAPRAST testing (by the way, we live in Ozzieland) - he may not have offered it to us because it was a first consultation and already the fee was $200 so I cannot imagine what it would've cost us if he had included the blood test. I will be regularly reading replies in this discussion board. It's lovely to know that I'm not just a paranoid mother and that there are lots of mums all over the world going through the same angst.

On May 12, 2002


Hi, just wanted to let you know if you have an allergist that believes not to Rast or Cap Rast till (I believe 2 or 3?) that's because some don't believe the blood tests are accurate until then. Some that do go through with such tests may have false positives.

On May 12, 2002

Unfortunately, skin testing can be inaccurate for children under the age of 2 as well- particularly those with eczema. Both tests improve considerably when combined with your observations and a good case history. As I understand it, many allergist simply don't believe in RAST testing which is dependent upon the skill of the lab analysing the results. Skin testing is accurate in *most* patients and is less costly so is often the test of choice. A CAP RAST (must be CAP brand) is said to be more accurate than the RAST with regard to peanut, egg and some other foods. If you want a baseline measure for future comparisons, the CAP is probably the way to go. BUT, you'll need to do your research and be able to talk to your doctor with real facts and figures or he or she may not take you seriously. It's been my experience that telling them that "someone online" told you about a test isn't as effective as saying "I read in Dr. Wood's book that...". The Peanut Allergy Answer Book is a hand guide for PA; for multiple food allergies and a good overall analysis of the science involved J. Brostoff's Food Allergies and Food Intolerances is pretty helpful. Also, there is a link in the research section here to an article title "Where We Stand"- it summarizes almost every major PA study done in recent years. After you've read that study you'll have some idea regarding just how up to date your own doctor is.