It seems
far-fetched, to be sure... but I'm not sure that I'm willing to call it "impossible."
Here's why: the few studies that have been done to establish a "safe" threshold dose for peanut have been abject failures (in other words, some of the patients react to the lowest doses, albeit with "subjective" symptoms), and those same studies often routinely exclude the most 'severe' patients in terms of reaction history. Understandable, of course, since a study should in general NOT provoke a life-threatening event intentionally, or even stand a reasonably liklihood of doing so, KWIM?
The kicker is that those same patients have often manifested the greatest SENSITIVITY (ie-- need the lowest doses).
People
can and most likely DO react to traces too low to be reliably detected in foodstuffs. Why should air sampling be different? Well, one can (arguably) pull more air through a filter/carbon cartridge in an attempt to make the "sample" larger, and therefore improve detection. But that assumes that you can recover what you've loaded onto your cartridge with 100% efficiency, and it assumes that your 'capture' device is perfect, too, and isn't allowing the analyte (proteins, or maybe even protein fragments) to be passed through the sampling device.
Therefore, my DH and I both (we're both PhD scientists and have excellent background in sampling and QA/QC for analytical methods) have some suspicions that this phenomenon may simply be one of the ANALYTICAL limit of detection (LOD) being far above the tolerated dose for a small minority of PA persons.
Bottom line is that we KNOW that this is more than a theoretical possibility-- canine noses can detect things that even the most sensitive of analytical detection devices (electron capture and mass spec, at the momet) can't touch. Why should this be different?
Therefore I'm not so quick to dismiss it as "impossible." Particularly not when I know what I've seen with my own two eyes. You'll have to take my DH's and my word for it, but we are NOT
looking for an aerosol explanation-- ever. But when to do otherwise stretches the limits of credibility it becomes the least implausible explanation (cross-contamination OF cross-contamination OF cross-contamination OF a surface in an environment routinely wiped down thoroughly, followed by possible, but unlikely, hand-to-face contact which nobody else saw... which resulted in airway symptoms FIRST, followed by other systemic symptoms). I'm truly not sure how else to explain facial hives, itching mouth and nose, and tearing, bloodshot eyes while an allergic child is CARRIED through a room containing the allergen in concentrated but undisturbed form-- not when that child is untouched by anyone but the parent (whose hands are holding the child) and the symptoms VANISH just as rapidly as they appeared once the parent and child are out into fresh air. I've seen this happen with my DD, and so have a number of our friends and acquaintances over the years. It didn't happen EVERY time, either... and not always when
I knew it was there...
I don't even pretend to know just how little protein must be involved in that situation. Truly. Now, I know that lakeswimr is going to come back and suggest that SOMEONE touched her, or that she must have been touching stuff outside of the room and that a surface was contaminated because the allergen was present... but I really have turned those explanations over in my head and they don't work all the time... and this was NOT psychosomatic. At 18-36 months old, I can't really think so, since my DD was not nervous about the presence/pictures/idea of pn-- only the SMELL of them.
I worry far less about skin contact than I do about inadvertent internal exposures, regardless of source or route of exposure. But with little ones, there's not much to separate the things, if you KWIM. Contact with hands BECOMES ingestion in a hurry.
Again, low-low-level aerosol reactivity really and truly is NOT most PA kids' reality. I know this. Not even most very sensitive kids' reality. But kids like mine
do exist, even if what they do seems to defy explanation. I bitterly regret teaching my daughter to try "toughing it out" in environments where she knew that there was aerosol exposure happening-- this is NOT a lesson that any FA child should learn... that some "bothersome" symptoms should be ignored in order to do things that one wants to do. They don't always stay just "bothersome" is the problem, and I didn't figure that out until I'd already conveyed that lesson to my DD. I wish that I hadn't listened to those who said that this was all in her head and that it was "not possible" for her to react other than by ingestion and that we were making her "neurotic" about her allergies by catering to her "psychogenic" symptoms.
We taught her to ignore what her body was telling her when we should have been teaching her that SHE knows her body better than anyone.
Sorry-- but this is an issue that really gets my dander up. I get sick of being judged even by other well-intended allergy parents as neurotic and over-protective, and so does my DD. This
is her reality, and while it makes her part of a VERY small subgroup even of severely affected FA people, it doesn't mean that she can ignore that reality. She does so at her own peril. Unfortunately, we
know that to be true.