Venom Reactions and Treatment Options

Bee (Hymenoptera) envenomation may include stings from honeybees, bumblebees, yellow jackets, hornets, and wasps – and the ASPCA Animal Poison Control Center warns that components of venom can create cellular injury, elicit an inflammatory response, trigger histamine release and act as a possible allergen.

Envenomation from fire ants can cause similar signs.

3 Reaction Types

Local reactions, systemic poisonings, and allergic reactions can occur with bee envenomation.

1. Local reactions tend to be mild in nature and generally involve only a small number of stings. Wheal formation, pain, irritation, and pruritus at the site of the sting are common findings. While not common, stings in the mouth or throat may lead to respiratory compromise secondary to swelling.

   Signs from local reactions will generally resolve within a few hours; oral antihistamines, topical corticosteroid creams, and icing may provide relief in the meantime. Removing the stinger, if still present, as well as washing the area is important.

2. Systemic poisonings are more common with multiple stings and may result in edema, pain, vomiting, diarrhea, depression, coma, tachycardia, hypotension, tremors, seizures, rhabdomyolysis, acute renal injury, hepatopathy, coagulopathies, thrombocytopenia, hemolysis, hypoglycemia, acidosis, and electrolyte disturbances.

   With multiple stings, a patient should be monitored in clinic for a minimum of 6 – but ideally 24 – hours. If a patient displays systemic poisoning signs he or she will likely need to be hospitalized for multiple days.

   As with local reactions, an attempt to remove the stinger should be made. Baseline CBC, chemistry, electrolytes, and urinalysis should be obtained and these values should be monitored if clinical signs are noted. Electrocardiogram and blood pressure should also be serially monitored. Coagulation profiles may be needed in more severe cases.

   Treatment may include aggressive fluid therapy with monitoring urinary output, vasopressors, pain control (aggressive pain control may be warranted), antioxidants such as N acetylcysteine, diphenhydramine, anti-seizure medications, oxygen, gastroprotectants, and transfusions. 

3. Allergic reactions can be mild to severe in nature. For allergic reactions, antihistamines, corticosteroids – and, in severe cases, epinephrine – may be warranted in addition to supportive care.