Exactly, ultramarina. False positives are a huge problem diagnostically.
The other thing that non-allergic families
really ought to bear in mind (and WOW, do I wish
everyone knew this ONE thing, if they know NOTHING else):
Epinephrine is the ONLY thing that you can do. It's not a get-out-of-death-free card. You can do everything right and STILL die if you anaphylax. That is the thing that even most parents of food allergic kids don't really want to think about. Sure, we carry epinephrine everywhere, practice and plan to use it, and educate ourselves and others about doing so... but the bottom line is that it's kind of Russian Roulette, flirting with allergen exposure. Epinephrine MIGHT help save your life, and it's certainly the best that anyone
can do outside of an emergency department, but it's nothing like a guarantee. At all.
Natalie Giorgi's death is highly instructive that way. People (like my DD) who have a history of very severe, very RAPID anaphylaxis, very low eliciting doses, and/or very unusual presentations (cardiovascular symptoms
without cutaneous ones, for example) may make their risk of fatal outcomes unspeakably high. So yeah-- we are VERY aggressive about avoidance, because "treatment" doesn't seem so promising in her case in particular. "Recognition" that we're dealing with anaphylaxis (and not another illness, not just anxiety, etc.) is not even all that good in our situation in particular.
There IS no situation in which we can "rule out" an allergic reaction. I say that even though our home has been free of the most potent of those food allergens for the past fourteen years. We estimate that the threshold dose needed for some of her food allergens is likely to be less than 10mg. On an average day.
If I had a nickel for every time I've been asked why I haven't just "taught my kid what she can't eat," though, I'd be a very wealthy woman. {sigh}
I've often been tempted to respond with "Because it was far more valuable for her to learn that other people can't be trusted, but that she shouldn't take it personally-- just don't take food from anyone, no matter what they say."
