I had one more idea, after reading Pete's post and the post about the epi-pen.

When I was in my late teens, I worked as a lifeguard and was the lifeguard who got to treat the most injuries. The most common minor injury I dealt with were bee stings. The best remedy I had for them was a paste made from baking soda and ammonia. It usually got the kids to stop crying rather quickly. Cheap too.

This of course was not for anyone showing signs of anaphalactic shock, but handling that would have been totally out of my league.