Which symptom indicates a severe allergic reaction requiring immediate epinephrine?

• A. Sneezing
• B. Swelling of lips and tongue with trouble breathing
• C. Headache
• D. Nausea

Answer: (B)

Airway and breathing problems from an allergic reaction signal a life-threatening situation. When swelling of the lips and tongue occurs with trouble breathing, it indicates airway edema and possible anaphylaxis, which can progress rapidly. Epinephrine is given immediately because it narrows blood vessels to reduce swelling, relaxes the airways to improve breathing, and helps stabilize blood pressure. The other symptoms—sneezing, headache, or nausea—can be related to milder allergic reactions or other issues and do not by themselves show the dangerous airway involvement that requires immediate epinephrine. If anaphylaxis is suspected, treat promptly, monitor the patient, and seek additional help.