A 21-year-old college senior comes to the university health clinic complaining of shortness of breath and cough for the past 2 weeks. He has just transferred to this university in Chicago from his home town in Arizona, where he had studied for the past 3 years. Each evening, on returning from classes to his dormitory room, he develops a dry non productive cough that typically lasts for several hours before he falls asleep. He is awakened from sleep with shortness of breath,cough, and wheezing. He denies cigarette smoking, bu drinks several beers on weekends and has occasionally smoked marijuana. Symptoms often occur on weekends, when he spends time studying in his dormitory room. On physical examination, he denies any respiratory symptoms, and his lung examination is normal. Which of the following is the most likely mechanism for his symptoms?
A. Bronchospasm
B. Laryngeal spasm
C. Pleural effusion
D. Pulmonary congestion
E. Ventilation-perfusion mismatch
A. Bronchospasm
B. Laryngeal spasm
C. Pleural effusion
D. Pulmonary congestion
E. Ventilation-perfusion mismatch