What is the first step in the management of a patient with suspected severe allergic reaction?

The first step in the management of a patient with a suspected severe allergic reaction, known as anaphylaxis, is the administration of epinephrine. In cases of anaphylaxis, the rapid onset of symptoms can lead to life-threatening complications, such as airway swelling and shock. Epinephrine acts quickly to counteract these effects by causing vasoconstriction, increasing heart rate, and bronchodilation, which collectively work to stabilize the patient’s condition.

While providing oxygen, administering intravenous fluids, and giving antihistamines are also important components of treatment, they are not the immediate priorities in an anaphylactic reaction. Oxygen can help support the patient’s respiratory status but does not address the underlying allergic response. Intravenous fluids may be necessary later if the patient is in shock due to fluid depletion or vasodilation, and antihistamines help to alleviate symptoms but have a slower onset and should not replace epinephrine in acute management. Therefore, administering epinephrine is crucial as the first actionable step in responding to a severe allergic reaction.