Which statement correctly differentiates PVFM from asthma?

• A. PVFM causes throat tightness during inhalation; asthma causes chest tightness affecting inhalation and exhalation.
• B. PVFM affects lower airways only.
• C. PVFM and asthma both exclusively affect upper airways.
• D. PVFM responds well to inhaled steroids; asthma does not.

Answer: (A)

The key idea is that PVFM is an upper-airway problem at the level of the vocal cords that mainly affects breathing in during inspiration, whereas asthma is a lower-airway inflammatory condition that typically causes symptoms during expiration. With PVFM, the vocal cords paradoxically adduct when you breathe in, leading to throat tightness or inspiratory difficulty and sometimes inspiratory stridor. In asthma, the airways below the vocal cords tighten and swell, producing chest tightness, coughing, and wheeze that are usually more evident during exhalation due to expiratory obstruction.

So the best statement captures this distinction: inspiratory throat tightness from PVFM versus chest tightness related to lower-airway obstruction in asthma. Additional context: PVFM often shows normal lung function between episodes and is confirmed with laryngoscopy during symptoms, while asthma shows reversible expiratory obstruction on spirometry and improves with bronchodilators and anti-inflammatory inhaled therapies.