Which population is commonly affected by primary spontaneous pneumothorax?

• A. Young, tall men who smoke with no significant lung disease
• B. Older adults with COPD
• C. Infants with bronchiolitis
• D. Athletes with exercise-induced asthma

Answer: (A)

Primary spontaneous pneumothorax most often occurs in young, tall men who smoke but have no significant lung disease. The idea behind this is that tiny apical blebs or bullae can rupture spontaneously, letting air into the pleural space. Being tall and thin places the lung apices under greater negative intrapleural pressure, which makes blebs more likely to form and rupture; smoking accelerates bleb formation and inflammation, increasing the risk even when the lungs are otherwise normal. So this population fits the classic profile for PSP. By contrast, older adults with COPD are more prone to a secondary pneumothorax due to existing lung disease, while infants with bronchiolitis or athletes with exercise-induced asthma don’t represent the typical PSP demographic.