Hymenoptera Stings

Epidemiology: The hymenoptera include bees, wasps, hornets, yellow jackets, and ants. About 100 deaths from hymenoptera stings occur annually in the United States, nearly all due to allergic reactions to venoms. An estimated 0.4-4.0% of the U.S. population exhibits immediate-type hypersensitivity to insect stings.
Clinical features:
- Uncomplicated stings cause pain, a wheal-and-flare reaction, and local edema that subside within hours.
- Multiple stings (e.g., from wasps, hornets, ants) can lead to vomiting, diarrhea, generalized edema, dyspnea, hypotension, rhabdomyolysis, renal failure, and death.
- Large (>10-cm) local reactions (e.g., with erythema, edema, warmth, tenderness) progressing over 1-2 days are not uncommon; while they resemble cellulitis, they are in fact hypersensitivity reactions. Such reactions recur on subsequent exposure but are seldom accompanied by anaphylaxis.
- Serious reactions occur within 10 min (and rarely >5 h) after the sting and include upper airway edema, bronchospasm, hypotension, shock, and death.

TREATMENT
Hymenoptera Stings Stingers embedded in skin should be removed promptly by grasping with forceps or scraping with a blade or fingernail. The site should be disinfected and ice packs applied to slow the spread of venom. Elevation of the bite site and administration of analgesics, oral antihistamines, and topical calamine lotion may ease symptoms. Anaphylaxis is treated with epinephrine hydrochloride (0.3 mL of a 1:1000 solution, given SC q20-30min as needed). For profound shock, the pt should be transferred to a hospital emergency room. Pts should be observed for 24 h for recurrent anaphylaxis, renal failure, or coagulopathy. Pts with a history of allergy to insect stings should carry a sting kit and seek medical attention immediately after the kit is used.