Thinking about this some more (after all the challenges we had in FCPS . . . )
Propose a solution to nurse:
One epi will be in child's classroom at all times (out of reach of other children, yet UNlocked). Child will wear epi-pen on person using something like Spibelt product:
http://store.spibelt.com/Kid-s-Belts-s/22.htmREI and some sporting goods stores in area carry this or similar, if you want to see in the flesh.
And then there should be back up pair in office.
(Be sure to check what you have for EMT level available to your school -- some do not carry epinehrine, so you need the extras to go with child in ambulance, in event anaphylaxis recurs and have not reached medical facility.)
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It *may* be that the nurse's problem with self-carry is the too-accessible-by-others backpack?
Child may remove belt for P.E. and the P.E. teacher on duty must wear/carry.