I know a fellow who keeps honey bees and has been stung numerous times with no problem. All at once, a couple of years ago, he was out tending hives by himself and got stung. He started swelling up, having difficulty breathing, and about didn't make it back to his truck. He had to drive himself to the ER because he had never carried an Epipen. He carries one now.
Yeah once you have the allergic reaction, it gets worse with every encounter. I would say his bee keep days are done. Odd for it to happen out of the blue after so many years.