Bella was stung by a bee just by her nose a few weeks ago - we put a bite/sting cream onto it (after taking the sting out) and that seemed to help. In the Bruce Fogle dog care book it says to apply a hydrocortisone cream if you have any, and bicarb of soda for bee stings, vinegar for wasp stings, and an ice pack if possible.
Bella was subdued (a bit shaky and seemed to almost fall asleep at one point) for about half an hour but then seemed okay apart from looking a bit odd!