on the rise
It is true that the incidence of peanut allergies has risen dramatically in recent years. No one is sure why, but there are various theories. Vaccinations prevent children from getting the diseases that build up their immune systems; antibacterial products create "superclean" homes so that children don't build up immunities; it goes on and on.
Unfortunately, for some people even the most remote contact with peanut residue can cause a life-threatening reaction. This is rarely true of other food allergies, which can be serious, but not usually to this extent. I don't know why peanuts are such a danger, but the fact is they are.
If you have a designated "peanut-free zone," perhaps a student in your school has been identified with this allergy. Some schools ban peanut products altogether.