My friends youngest son has an allergy to peanuts.
My friend was asking the same thing about where the hell this came from.
The doc gave some mumbo jumbo about people getting healthier but the body changing and some other crap.
For awhile he gave his son one shot for emergencies but now, gives him 2 emergency needles to carry.
Its really heart breaking watching a kid have to learn how to use a needle "just in case".
It might have something to do with peanut products used in more and more foods which can cause sensitization, esp. when fed to younger children. Just speculation...