From ABC News:
3.3% of adults will experience anaphylaxis due to insect sting, 40 deaths are reported annually. People who develop anaphylaxis after being stung have a 60-70% chance that future stings will cause a similar reaction.
Chances of a reaction with a future insect sting decrease over time, but still remain at about 20% many years after the last sting. With insect allergy, "most people tend to have the same kind of reaction, same severity the next time. Once the allergic sensitivity in your system, any future sting could cause a systemic reaction."
Venom insect therapy was developed in the 1970s at Johns Hopkins University.
Mind map of insect venom allergy.
Anaphylactic Shock Due to Bee Sting
Venom Allergy: A Short Review. V. Dimov, 08/2007.
CNN: Skateboarder's death underscores insect allergy risks. 5 percent of Americans are at risk for a severe, potentially life-threatening allergic reaction from insect stings http://bit.ly/3PEVtK
Image source: Wikipedia, GNU Free Documentation License.