Disclaimer: I'm about to discuss blood testing, food trials and food challenges.
This is just a recount of my personal experiences and thoughts. I am not a doctor, so please discuss any questions you may have with your allergist or physician.
So, I'm finally getting around to my follow-up to my previous post about Morgan's latest round of food allergy blood testing. That post focused on the downward trend of her peanut and milk specific IgE (sIgE) levels and her total IgE, but we tested other foods, as well.
I was interested in seeing if we might be able to challenge some foods that were in a questionable "gray area" in her clinical history. These two foods were beans, peas and sesame.
The lab tested for a kidney/pinto bean mix. (How does that work? Do they blend up both kinds of beans into a single sample? Are the isotopes identical?) My allergist previously insisted that I not try beans, as they cross-react with peanuts, but I explained that my daughter eats other legumes, like soy and green beans, without issue. The value came back as 1.65, which is even lower than my daughter's 18-month soy result, which was 1.95 and she is not allergic to soy. My allergist agreed that I should be able to try pinto beans at home, as I recall my daughter eating a pinto bean, a couple of times, without incident. Now, this is all easier said than done, because I have such a hard time deciding on a day to try a new food. Well, it's not entirely new, but it has been a long time since she had that last uneventful pinto bean.
When my daughter was younger, I gave her some canned "peas and carrots" and she sprouted a few very tiny, hives on her upper lip. I think she had eaten "peas and carrots" a couple of times before that, but I just don't remember if any hives popped up those times. After seeing suspicious spots, I put them on the "no" list. Though I don't necessarily want my daughter to eat canned peas, pea protein happens to be used in some allergy-friendly substitutes. The test result came back as 2.29, so the allergist thinks we need to continue to avoid it, since I think she had some kind of reaction to it, in the past.
I don't think my daughter has ever eaten sesame, before. Her value back when she was 2 1/2 was 15.5 and I felt that was too high to mess with, but the allergist disagreed. I never challenged it and decided to wait until the latest results. The sesame sIgE came down to 4.27, and even though the values are from different labs, they were both Phadia 1000 ImmunoCAP tests, so I feel they are pretty comparable. The allergist said she could do an in-office food challenge for that one if I wanted. We'll see if/when I get up the nerve to do that.
We also revisited the issue of my daughter's flax seed allergy. Flax is such a pain in the gazoo. It's not a Top 8 allergen, so it's not labeled and no companies mention/care about cross-contamination. Plus, it's the additive du jour whenever a company wants to be able to slap "Omega-3" into their offerings. I find flax to be the most irritating of my daughter's allergens, as far as management issues go, because it eliminates entire product lines, due to cross-contamination risks. I'm sure those of you dealing with corn allergies are sitting there thinking, "oh, you think you have it bad?" so I will stop whining, now, but I think I have explained my current feelings for flax. This is an allergen I'd love to see G-O-N-E. Two years ago, her labs showed 28.2 and this year they came back 5.65. With a history of reactions to flax seed, the allergist did not think this one would be ready to challenge for a while longer. She also thought it wasn't the greatest candidate for an in-office food challenge, because my daughter's reactions, though one was ER-worthy, were delayed. She said we might have a scenario where we challenge the flax, she looks fine in the office, then in the middle of the night, we wake up with problems. Therefore, flax is still on the "no" list and we wait another year to see how the numbers change.
Even though I know my daughter is allergic to mustard, I decided to test for it, just to see the sIgE value. Mustard came back 5.86. I find it curious that her mustard value is just 0.03 away from coconut, to which she is not allergic. This just goes to show that each food has its own "scale" and you can't really compare sIgE values of different foods, nor can you really compare other people's IgE too directly, either. It really is a combination of what the history shows, along with some additional clues that some sIgE values can provide. The nerve-racking truth of the matter is that we will probably have to challenge many of these foods, at some point, but the silver lining is that challenging them would mean that we're hopeful that the allerg(ies) have resolved.
And so the wait continues...