A 10-year-old boy complains of wheeze and chest tightness that occurs only during football practice and settles within 30 minutes of stopping play. Resting spirometry and baseline examination are completely normal between attacks. Which investigation will best confirm the diagnosis?
- A High-resolution CT of the chest
- B Sweat chloride estimation
- C Exercise challenge test measuring fall in FEV1 ✓
- D Arterial blood gas analysis
Correct answer: C. Exercise challenge test measuring fall in FEV1
Explanation
Exercise-induced bronchoconstriction causes symptoms only during or shortly after sustained aerobic exercise, and lung function between episodes is typically normal, so resting spirometry cannot confirm it. An exercise challenge showing a fall in FEV1 of 10 percent or more from baseline confirms the diagnosis. HRCT and arterial gases are irrelevant in a child with normal resting function, and sweat chloride tests for cystic fibrosis, which presents differently.
Reference: Nelson Textbook of Pediatrics, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.