How long after a bee sting does anaphylaxis occur?

Short time: Usually within minutes to under an hour..Rarely severe symptoms can occur two hours or so later. If you have had serious symptoms after a sting in the past see an allergist asap. There is good testing and a treatment that can essentially " cure" you. Don't hesitate.

Seconds to 2 hours: Generally the sooner the onset of symptoms the worse the reaction. So the ones that start within a minute or two after a sting turn out to be statistically the deadliest. You may not even have time to find your epipen! but venom immunotherapy cures 99% of patients with anaphylaxis to bee stings. If you are allergic to bees, wasps or hornets you should be on venom shots. Period. End of story.