What action most critically improves survival when anaphylaxis is recognized?

• A. Administer high-flow oxygen first
• B. Administer epinephrine promptly
• C. Administer antihistamines first
• D. Initiate IV antibiotics

Answer: (B)

An immediate intervention that reverses the life-threatening aspects of anaphylaxis is epinephrine given promptly. Epinephrine acts on multiple pathways to stabilize the crisis: it constricts blood vessels to raise blood pressure and reduce swelling in the airways, and it relaxes bronchial smooth muscle to relieve bronchoconstriction. It also helps limit further release of inflammatory mediators from mast cells, slowing the whole reaction. Because these effects directly address the dangerous changes in breathing and circulation, giving epinephrine first and without delay markedly improves survival.

Supportive measures like high-flow oxygen help with oxygenation but don’t halt the underlying process, while antihistamines mainly relieve symptoms and don’t prevent airway compromise or shock. Antibiotics aren’t part of acute anaphylaxis treatment unless there’s a separate infection. If epinephrine is available, administer intramuscularly (usually 0.3–0.5 mg of 1:1000 solution for adults) as soon as anaphylaxis is recognized, and repeat the dose every 5–15 minutes if symptoms persist or recur.