My son developed an allergy to apples (then carrots and celery) when he was 10 - he'd get hives all over his face and neck, his lips would swell and tongue would be itchy. The allergist explained that enzymes in certain fruits and vegetables react with airborne pollens. The thing is, those enzymes are broken down during cooking. Ds can be around those things and even eat them if they're cooked with no reaction - he eats applesauce every day. While your manager's reaction *sounds* a little over the top, keep in mind that there are people whose allergies to, say nuts, are so severe that they can't even be in the same room as their trigger.