What is the first-line treatment for anaphylaxis?

• A. Epinephrine administered subcutaneously
• B. Antihistamines alone
• C. Corticosteroids alone
• D. Oxygen therapy only

Answer: (A)

Epinephrine is the immediate treatment because it counteracts the main life-threatening changes of anaphylaxis: shrinking the dangerous swelling and fluid leakage with alpha-1 effects, and reversing bronchospasm and low blood pressure with beta-1 and beta-2 effects. This rapid action improves airway patency and circulation much faster than any other medication alone, which is why it must be given first.

In practice, the preferred method is an intramuscular injection into the mid outer thigh, providing quick and reliable absorption. Subcutaneous administration has slower uptake and can be less dependable in severe reactions, which is why intramuscular delivery is emphasized in guidelines. After giving epinephrine, you should monitor the patient closely, provide supportive care (including fluids and airway management if needed), and address symptoms with additional treatments as needed. Antihistamines and corticosteroids don’t reverse the acute airway and hemodynamic compromise quickly enough to be first-line, and oxygen alone does not treat the underlying pathophysiology.