Epi pens are not a cure all. You inject epiphrine into your child ( it is adrenaline) and you have approximately 15 minutes to get to a casualty department before it wears off. A common reason why anyone in more rural areas have to multi dose.
So what is better for the child with the nut allergy:
1. Being injected with hormones/adrenaline/epiphrine every day if they come into contact with nuts, or come into contact with someone else who has been eating nuts. Then having them whisked out of school every day to an emergency room in a hopefully nearby hospital.