Grading Reactions to Hymenoptera (Wasp, Bee, Ant) Stings

The Hymenoptera (wasps, bees, ants) are common insects whose stings cause significant human morbidity and mortality.

Reactions to stings:

(1) toxic, which can be significant if the victim is small, or elderly or the number of stings is very large

(2) allergic, with anaphylactic the most severe

Group	Reaction	Description
local swelling at the site of the sting	typical	<= 10 cm
	large	diameter > 10 cm and lasting > 24 hours
systemic	grade I	generalized urticaria, itching, malaise, anxiety
	grade II	grade I, plus >= 2 of the following • angio-edema (grade II if alone) • constriction of chest • nausea • vomiting • diarrhea • abdominal pain • dizziness
	grade III	any of the above, plus >= 2 of the following • dyspnea (grade III if alone) • wheezing (grade III if alone) • stridor (grade III if alone) • dysphagia • dysarthria • hoarseness • weakness • confusion • feeling of impending doom
	grade IV	any of the above, plus >= 2 of the following • fall in blood pressure • collapse • loss of consciousness • incontinence of urine or stool • cyanosis
unusual reactions	serum sickness	fever, arthritis, lymphadenopathy, exanthema, vasculitic purpura, generalized vasculitis
	renal	glomerulonephritis, nephrotic syndrome, acute renal failure
	neurologic	peripheral neuritis, polyradiculitis, epileptic seizures, reversible CNS damage, irreversible CNS damage
	hematologic	thrombocytopenia, hemolytic anemia, DIC
	cardiac	angina pectoris, myocardial infarction

Fatal reactions:

(1) tend to occur following stings to the head and neck

(2) may be due to a variety of mechanisms but usually interfere with respiration or cause anaphylaxis

(3) most fatalities occur quickly after the sting

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