The sting may be painful for a few hours. Swelling and itching may persist for a week. The area should not be scratched as it will only increase the itching and swelling. If a reaction persists for over a week or covers an area greater than 7-10 cm (3 or 4 inches), medical attention should be sought.
Doctors often recommend a tetanus immunization. For about 2 percent of people, anaphylactic shock from certain proteins in the venom can be life-threatening and requires emergency treatment by a physician. If the victim is allergic to bee stings, the victim must be treated to prevent shock. People known to be highly allergic may carry around epinephrine in the form of a self-injectable Epipen for the treatment of an anaphylactic shock. - WIKI
The pain will usually go away pretty quickly, but swelling may last for more than a day. Use an ice pack to reduce swelling at the site.
Take the victim to the emergency department if the victim was stung more than 10 times, or if there are bee stings inside the nose, mouth, or throat. Swelling from these stings can cause shortness of breath, even in non-allergic victims. - ABOUT.com
It's common to develop some itching at the bee sting site. Antihistamines or calamine lotion should help.
NVDL: It's the second time this year that I have been stung. The first time I was in a bike race so did not remove my helmet and the sting had the opportunity - wind notwithstanding - to take full effect.
On a training ride yesterday I immediately removed my helmet and asked that a friend remove the sting.
It turns out that one should remove the sting immediately, and that it doesn't matter how. Also interesting is that bee venom is the only insect toxin specifically evolved for mammals.
24 hours after my sting I can barely see out of my eyes as my tear ducts and the bags under my eyes are fully inflated. This reaction occurred quicker than my first sting. It is possible the bicycle race allowed the toxin to distribute, to some extent, in my bloodstream. On the other hand, I have used antihistamines which, I have to say, have had no impact other than to make me drowsy.
I think the reason I was stung was that the bee and me were both in the wrong place at the wrong time. Probably the bee didn't see me coming. Touche.
Honeybees a vital hazard
Couple of stings a day takes the sting out of bee stings
All of these insects aggressively defend their nests, although they have not developed a sting targeted at mammals like the honey bees.
The bee's sting evolved originally for inter-bee combat between members of different hives, and the barbs evolved later as an anti-mammal defense: a barbed sting can still penetrate the chitinous plates of another bee's exoskeleton and retract safely. Honey bees are the only Hymenoptera with a strongly barbed sting, though yellowjackets and some other wasps have small barbs.