A patient develops a rash on the neck and experiences difficulty breathing minutes after receiving local anesthesia. What is the appropriate action?

• A. Give Epinephrine
• B. Give Benadryl
• C. Stop treatment and observe
• D. Administer a placebo

Answer: (A)

When a patient shows systemic symptoms after local anesthesia—such as a spreading rash and new onset breathing difficulty—the situation is anaphylaxis, a medical emergency that requires immediate treatment to open the airway and restore circulation. The first-line intervention is epinephrine because it rapidly reverses airway edema and bronchospasm, constricts blood vessels to support blood pressure, and reduces further mediator release from mast cells.

In this scenario, the best action is to administer intramuscular epinephrine promptly. For an adult, give 0.3 to 0.5 mg of 1:1000 epinephrine into the mid-anterolateral thigh. If symptoms persist or recur, repeat every 5 to 15 minutes as needed. After giving epinephrine, call for emergency services if they are not already involved, monitor the patient, provide supplemental oxygen if available, and ensure the airway is supported.

Why the other options aren’t appropriate as the primary response: antihistamines like diphenhydramine do not treat the airway obstruction or shock quickly enough and are not sufficient alone for anaphylaxis. Stopping treatment and simply observing delays life-saving therapy. Administering a placebo would not address the life-threatening reaction.