In suspected anaphylaxis from a bee sting, what is the recommended first-line treatment and route?

• A. Administration of epinephrine IM 0.01 mg/kg 1:1000
• B. Diphenhydramine PO 25-50 mg
• C. Dexamethasone IV 1 mg/kg
• D. Diphenhydramine IV 25-50 mg

Answer: (A)

Prompt epinephrine given intramuscularly is the best first-line treatment for suspected anaphylaxis from a bee sting. Epinephrine rapidly counteracts the life-threatening features of anaphylaxis by constricting blood vessels to raise blood pressure and reduce capillary leakage, while also increasing heart output and relaxing bronchial smooth muscle to relieve airway constriction. The intramuscular route into the mid-anterolateral thigh provides the fastest, most reliable absorption in an emergency setting.

The dosing is 0.01 mg/kg using a 1:1000 concentration, given by intramuscular injection, with repeat dosing every 5-15 minutes if symptoms persist or recur (adult typical per-dose maximum around 0.3-0.5 mg; pediatric dosing scales with weight). While antihistamines and steroids can be added later, they do not reverse the acute airway and circulatory compromise as quickly as epinephrine and are not substitutes for it in the initial management. IV epinephrine is reserved for hospital settings under close monitoring due to higher risk of rapid adverse effects. After administering epinephrine, monitor the patient closely, ensure airway support is available, and arrange for rapid transport for continued observation and treatment.