Theories abound. I've heard similar theories regarding the beneficial effects of ingesting (or injecting) small amounts. I look forward to controlled studies.
Dr. Sampson did some of the original double-blind food challenge protocols that my son  was involved in many years ago. He certainly is a pioneer in the field.
BTW - I simply *hate* the word "outgrow." It's mentioned so much, but is not universal. My allergies were adult-onset (is that "in-grow"?) and my son is in the "allergic 2%," and is thus not expected to outgrow any of his.
I guess the reason I so hate it is that it was the last resort of many doctors who watched my son tearing at his skin, unable to help him, saying that in a few years he might outgrow his allergies. Had we waited for that and not sought ways to eliminate the triggers, I doubt he'd still be alive. Now he's a thriving 17-yr-old.
Down from soapbox.
Mark