So, just for fun, I dug around and found the last labs for DS1. On it they had Walnut (F256) ... which when you just plug that into a google search comes up (first result)
http://www.questdiagnostics.com/testcenter/TestDetail.action?ntc=3489 and it lists Black Walnut.
Now, most info I can find talks about most people eating and using the English Walnut. I'm sure it is that typically light brown walnut meat that you just find in most packs in baking aisles right?
What were your DD's numbers again for walnut that led to her taking an oral challenge? Were they low, but low enough to make the doc think an oral challenge was okay, or were they at 0?
I'm wondering if you could lab test low, with Black Walnut, and not be allergic to English Walnut. So, if you do the oral challenge with English then you pass, but still have an allergy to Black Walnut..... because low numbers don't always mean you pass the oral challenge.
Is there a way to get more specific labs done?