To answer cath127 question my son was tested after having a reaction for eating a choc.chip cookie that had a little bit of peanut butter in them. Never had peanut or nuts before that so we new. Then the test to confirm.
My pa son's twin sister although didn't react. She sounds a lot like 5boysrus son, she is the one with eczema, snores, sometimes frothing at mouth(pretty scary looking stuff, it looks like you could shave with it!) She catches every virus, is sick every other week(since 8 months of age). She was recently tested for 25 or more environmental and milk but Not Peanuts since she doesn't eat them anyway. She wasn't allergic to anything. She is a mystery.

A reaction when he grabbed his sister's pb sandwich and took a bite.