Discuss trollsbane1's answer to: What to do for a swollen hand from wasp sting?

Make a paste of baking soda and water, put some directly on the bite.  It will help to neutralize the acid in the wasp venom.  Put cold packs on to reduce the swelling.  If the swelling doesn't start to go down within a few hours, or if the area around the puncture starts to discolor or turn red, get to an emergency room ASAP.