Thank you for the source!

I only order from Tierra Farms. The last few years I haven't really ordered them but once or twice.

Yes!  We live in the East and DD has horrible tree pollen allergies that are more manageable after 2 years of allergy shots that include tree pollen.

Mac, do you eat English Walnuts?  If so, how do you handle walnut as an ingredient?

I can't imagine a customer service person is going to know or be able to find out what kind of walnut is in a food's ingredient.

I've tested positive to black walnuts but not English walnuts.

If you live in the Eastern US, then I might suspect a pollen/OAS type sensitivity to black walnut since it's native there.  If the allergenic walnut proteins truly are the same or similar across all species of walnut, it might explain why she reacts to one but not the other.

DD's testing history:  (the science stuff I linked about the proteins I don't really understand....I am more art like, wish I was more science based, it seems so interesting... but I do know because  those numbers were low is why the allergist opted to food challenge walnut.

Walnut component testing done in September:
Walnut Food IGE 0.36
rJug r1 Walnut 0.1       http://www.phadia.com/en/Products/Allergy-testing-products/ImmunoCAP-Allergen-Information/Food-of-Plant-Origin/Allergen-Components/rJug-r-1-Walnut/
JUG R 3 LTP Walnut 0.1   http://www.phadia.com/en/Products/Allergy-testing-products/ImmunoCAP-Allergen-Information/Food-of-Plant-Origin/Allergen-Components/rJug-r-3-Walnut/

After the initial testing when she was little, we rarely tested individual tree nuts.

Historical CAP RAST results for "English Walnut":
2009 Class 2 0.97
2014 Class 2 1.47


Historical CAP RAST results for "Walnut" (no clue what kind but assumed black since tested in same year as English):
2009 Class 1 0.58

Still have not heard from the allergist, but I am assuming it will take a few days for the doctors to communicate back and forth.

Thus, one would not expect to find isolated sensitivity to black walnut.

Until the allergy world somehow can explain a lot of things that are not expected that somehow we have ended up dealing with I am not sure I would necessarily think a person couldn't have an "isolated sensitivity" to anything.

But, yeah, it is crazy to find out just how much there is to know about walnuts.

Did you hear back anything from any docs?

Quote from: gvmom on February 14, 2017, 06:32:05 PM
http://www.aaaai.org/ask-the-expert/cross-reactivity-black-walnut-english-walnut

I found the link above...... don't know if it is helpful or not.

This sort of reminds me of the old thread from ages ago about drupes/tree nuts.......

.... I have a feeling to really "know" you almost have to become an expert ..... and in your case, an expert on walnuts!

According to this link there are 4 kinds of walnuts!!!! "There are scant data regarding cross-reactivity between the four walnut species (English, black, Asian butternut, and American butternut). The data that do exist imply that there is strong cross-reactivity between all four (see abstracts copied below). Thus, one would not expect to find isolated sensitivity to black walnut."

Have they isolated anaphylaxis causing walnut protein component yet (like they have for peanut) and do they test for that yet?

Just wondering . . . rusty on testing stuff these days.

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? 

Black walnuts are not so readily available in many areas and usually more expensive, is what I've noticed.

I would suspect that English walnuts are what is in most stuff made with walnuts?  (Have not googled, just assuming due to cost and availability)

Having said that, who knows what other nuts (or peanuts) might be pacakged on same lines with either of those types of walnuts.  So that might complicate things for some?

FWIW, Black walnuts are more flavorful to me than reg Eng walnuts.

Just in skimming around, it does look like there could be big differences between the two types of walnuts. 

What I wonder is if typically whatever is used for FA testing is English, and that then is theoretically supposed to cover all Walnut..... when what they should do is break it up into Black and English.... separately tested. 

I would imagine, given that DS2 was allergic to "egg".... but then tested for the white vs yolk ..... because some things weren't making sense with his allergy.  He was allergic to yolk, which somehow was confounding.

Anyway..... do you have any of the lab results that list the info about allergens?  Is there any sort of listing of Walnut.... and if there is anything like English or Black as sort of a sublisting with separate numbers for each? 

Good Lord. English vs. Black - who knew?

http://www.aaaai.org/ask-the-expert/cross-reactivity-black-walnut-english-walnut

I found the link above...... don't know if it is helpful or not.

This sort of reminds me of the old thread from ages ago about drupes/tree nuts.......

.... I have a feeling to really "know" you almost have to become an expert ..... and in your case, an expert on walnuts!

Yes, the allergist said she should continue to eat those.