Insect Sting Reactions

Deaths occur every year from allergic reactions to insect stings. Many could be prevented if proper precautions are taken. As a general rule, local reactions (even very large ones) to insects such as hornets, bees, and fire ants, do not require any work-up or precautions. This is because these local reactions do not imply that the patient is at significant risk for severe allergic reactions like anaphylaxis.

In adults, any immediate systemic reaction (i.e., generalized hives, angioedema, wheezing, hypotension), no matter how mild, requires consideration for skin testing and immunotherapy. The reason being is that there is a very real chance of the patient’s next sting event being more severe.

In children, urticaria alone does not often portend a more serious reaction. So, only reactions involving respiratory or hypotensive symptoms should suggest the need for skin testing and immunotherapy. An exception to this rule of thumb might be Fire Ants. Some experts are suggesting that even hives alone may be reason enough to start shots in children. The reasoning is that these stings are so common (especially in the Southeast) and the reactions to them can be severe in certain individuals.

If a patient is sensitive, venom immunotherapy is up to 95% effective in protecting against a life-threatening reaction. Of course, all patients with a history of a systemic reaction should be given an Epipen™ or similar self-injectable epinephrine preparation. Also, these patients should consider ordering a medical alert bracelet, i.e., this may be of diagnostic help in the event of an arrest due to a hymenoptera sting. They should also be instructed on insect sting avoidance (see article “Allergic Reactions to Insect Stings” in patient information section).