I guess it's good to get stung by a few native species as a youth to figure out if you have any reactions. I can vouch I have no allergies to red wasps, yellow jackets, honey bees..
So could he. He'd been stung many times previous to that (He was in his early 60s at the time) and had never had a reaction. Now he's allergic to just about anything which 'stings' and has to carry at least one double ended epi-pen.
I always think about that when we go fishing by the North Saskatewan River and have to climb down a steep wooded face for 10 minutes to get to the river. Climbing out of that and getting to help would be hard even with the epi-pen...they only give you about 15 minutes of grace per dose.
If that's me one day, I'll be able to reach for the Reactine and get my butt to the hospital while my leg swells to 3 times it's normal size...only more slowly than it would have had I not been prepared.