Negative RAST but positive skin test - Peanut Allergy Information

Negative RAST but positive skin test

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Hello.. My three year old was diagnosed at 18 months due to hives around her mouth, swollen eyes and hands (wherever the PB had touched after she ate a PB&J). She's always had really low levels (starting rast was 1.31) and a skin test that was on the low side. When she was 2 years old her rast had dropped to 0.57, and at her 3-year checkup she tested negative on the rast. We were so excited, and had a skin test scheduled with the allergist. She would've followed with a food challenge had she passed the skin test. To our dismay, she failed the skin test. The skin test level had actually almost doubled :(

Is it possible that she's only contact allergic to peanut but would be fine if she ate it? She appears to be contact allergic only with her dog & cat allergy (they cause a rash if they lick her, but no other symptoms). She also tested positive to egg and milk but eats them daily with no issues.

The allergist won't do a food challenge test due to the positive skin test. Will some allergists do this? I would like to enroll her in the desensitization drops they have a a Wisconsin clinic, but would really like to see if it's even necessary first.

Has anyone done a food challenge at home (to a child like her who has never been anaphylactic)? Will the UKnow test help us make any decisions? Is it actually accurate and credible?


By Bernard on Sep 10, 2013

I would not risk it.our daughter had a positive skin test but nothing showed on her blood test for peanuts.the whole reason we had get tested was because she reacted the second time we fed her pb. She had hives, uncontrollable sneezing, itchy eyes.the allergist says if the skin test said yes, then that's what we are to go by.