Which life-threatening allergic reaction involves swelling of the airways, bronchoconstriction, and vascular leakage?

• A. Anaphylaxis
• B. Pulmonary edema
• C. COPD
• D. Spontaneous pneumothorax

Answer: (A)

Anaphylaxis is a rapid, systemic allergic reaction that causes swelling of the airways (airway edema), bronchoconstriction, and leakage of fluid from the vessels (vascular leakage). This combination can quickly compromise breathing and blood pressure, making it life-threatening. The swelling in the airway and the bronchoconstriction directly lead to severe breathing difficulty, while the vascular leakage can cause swelling in tissues and eventual shock if not treated promptly.

The other conditions don’t fit this acute, widespread allergic process: pulmonary edema is fluid buildup in the lungs typically from heart or fluid overload issues; COPD is a chronic inflammatory lung disease characterized by long-standing airflow limitation; spontaneous pneumothorax is air leaking into the pleural space causing lung collapse. The description—airway swelling, bronchoconstriction, and vascular leakage—best describes anaphylaxis.