Somewhere in BF is a thread about a similar bee encounter I had on a road ride. I inhaled a bee and it stung my tongue. I've had bad reactions in the past and happen to carry benadryl in my toolbag. I crunched up the pill and hoped for the best. Unfortunately, my tongue kept swelling so I stopped at a fire station to wait for it to subside. It still wasn't better and I ended up taking an ambulance ride to an emergency room. They had some kind of drip- I think it was simply more benadryl- and that did the trick.

It's no fun but makes a good story.