I'm not a doctor, so take this with a grain of salt, but IMHO peanut allergies are more psychological than physical. That is, demand that peanuts be banned from your environment, and you feel fine. Watch someone eat peanuts, and all of a sudden you feel sick. Never mind that actual peanut dust is all over the place in a cramped, rarely cleaned public place like an airplane.

I needed to go to the store to buy some toothpaste, and after reading this thread, I'm going to buy some peanuts as well. Mmmmmm....