Anaphylaxis (something I have to be keenly aware of with my allergies), is when the throat swells, causing asphyxiation (suffocation). It's the most extreme of allergic reactions.
This is what I have to be concerned about with my bee / wasp / mosquito allergy. For this reason, I do not handle scorps, tarantulas, or anything with a potential for venom, because I do have an overactive immune system.
- Ken LePage