Clinical meaning
Insect sting allergies are caused by venom from Hymenoptera order insects: bees (honeybees, bumblebees), wasps, yellow jackets, hornets, and fire ants. Normal local reactions involve pain, erythema, and swelling at the sting site resolving within hours. Large local reactions extend > 10 cm in diameter and last > 24 hours but carry low systemic anaphylaxis risk. Systemic allergic reactions range from generalized urticaria to life-threatening anaphylaxis with bronchospasm, laryngeal edema, and cardiovascular collapse. Prior sensitization with IgE formation is required for anaphylaxis. Each subsequent sting carries 30-60% risk of similar or worse reaction in previously allergic individuals. Honeybees leave stingers with venom sacs that continue injecting venom; scrape (don't squeeze) the stinger to remove. Venom immunotherapy reduces future anaphylaxis risk to < 5% and is recommended for patients with prior systemic reactions.
Exam relevance
Risk factors: - Previous systemic allergic reaction to insect sting - Outdoor occupations (landscaping, farming, beekeeping) - History of atopy increasing sensitization likelihood - Living in areas with high Hymenoptera populations - Concurrent beta-blocker or ACE inhibitor therapy (complicates anaphylaxis treatment)