okay
(so as the theory goes right now)
the use of various baby products (i.e. lotions, diaper rash creams, etc.) on newborn and infant children is believed to be the reason. these products contain peanut oil in them. the child's body somehow has a reaction to the use of this product and its absorbtion into the skin and getting into the blood stream. so over time and the constant use of the product in question, the peanut oil makes the child deathly alergic to peanuts. infant bodies are not supposed to be subjected to stuff like that. as a person becomes older, their body can handle such things due to their immune systems getting stronger.
and as i said, this is the theory currently. but i don't care if it is only a theory, when i have children i am not using products with peanut oil in them.