More on possible causes of peanut allergy.
http://www.sciencenews.org/articles/20030315/food.asp
Seems there is some hope for eventually developing a treatment.
http://www.sciencenews.org/articles/20030315/fob1.asp
We've encountered one case of peanut allergy so far, one year a child at the kids' preschool was allergic so peanut and peanut butter were banned from school lunches. It wasn't any big hardship. Its just peanuts, a second-tier snack . . . be glad there's not a similar allergy to beer, or beef.