There is also evidence that some vaccines could be causing peanut allergies. In 1995 a sudden tidal wave of Kindergartner's appeared in school with peanut allergies. That means something happened in 1990 when they were born.
This site has an interesting overview of how that likely happened.
http://thinkingmomsrevolution.com/whats-really-behind-peanut-allergy-epidemic/
(p.s. You should do an @introduceyourself post soon. Some people won't vote for your posts until you prove that you are real person.)