The severity of a reaction after multiple wasp stings depends on two key factors: the total venom dose and the cumulative risk of an allergic reaction.

The amount of venom injected in a single wasp sting is about 0.

5–2 Îŧl (microliters) — for a non-allergic adult, this amount of venom typically causes only localized pain and swelling.

Multiple stings (e.

, disturbing an entire nest and being attacked by tens to hundreds of worker wasps simultaneously) can bring the total venom dose to a dangerous level.

The main toxic components in the venom — melittin and phospholipase A2 — once they exceed a certain threshold concentration, can cause: massive cell lysis (melittin directly disrupts cell membranes), rhabdomyolysis (release of skeletal muscle cell contents into the bloodstream), and acute kidney injury (muscle proteins and hemoglobin clogging the kidney filtration system).

Allergic reaction is a separate and independent risk factor — even if previous stings caused only mild reactions, the level of IgE antibodies produced by the immune system can progressively increase with each sting.

The next sting could trigger a much more severe allergic reaction than the last — ranging from widespread hives to anaphylactic shock.

Individuals with a history of breathing difficulty or facial swelling after a single sting should carry an epinephrine auto-injector for life and take extra precautions against stinging insects during outdoor activities.