but not OK for a crew member with a mild allergy. Gotya
Well, no, that's not really what I said at all ! If an allergy is MILD, and proven to be so, and not life-threatening, then the cabin crew would have no problem working, AND FURTHERMORE would NOT have to interfere with a passenger's personal choice of on board snack.
it's ok for a passenger with an extremely severe allergy to nuts to travel at 37,000 feet (we've had quite a few travel with us who have severe allergy and carry an Epipen)
That's NOT QUITE in the spirit of what I said either ! If a passenger is known in advance to be very likely to suffer a life-threatening episode in flight, then no airline in its right mind should carry them ! My point was that, unlike staff, they fly infrequently, and facts are unpredictable, and often not known until the flight is well on its way.
Any "problem with breathing", especially at high altitude, is hardly well associated with the word "mild". The third line of Gingernut's very succinct post may well be the key to this one. I agree with his last line too.