Capsaicin cough receptor sensitivity test in children

Area of Science:

• Pediatric Pulmonology
• Respiratory Physiology

Background:

• Capsaicin is used to assess cough reflex sensitivity in adults.
• The utility of this test in children requires evaluation for tolerance, repeatability, and influencing factors.

Purpose of the Study:

• To assess the tolerance and repeatability of the capsaicin cough challenge test in children.
• To investigate the impact of inspiratory flow rate on cough receptor sensitivity in pediatric subjects.

Main Methods:

• Thirty children (aged 6-16 years) underwent capsaicin nebulization to determine cough thresholds (Cth, C2, C5).
• Tests were conducted on two separate days, with subjects regulating inspiratory flow.
• The influence of varying inspiratory flow rates (20 L/min vs. 60 L/min) was examined.

Main Results:

• The capsaicin cough challenge test demonstrated good tolerance and high repeatability in children.
• A significant increase in cough thresholds (C2 and C5) was observed with higher inspiratory flow rates (60 L/min compared to 20 L/min).
• Doubling dose changes indicated high reproducibility for Cth (1.08), C2 (1.13), and C5 (1.03) at a constant flow rate.

Conclusions:

• The capsaicin cough challenge test is a safe and reproducible method for evaluating cough reflex sensitivity in children.
• Inspiratory flow rate significantly affects cough receptor sensitivity and test repeatability, necessitating controlled administration.
• Standardizing inspiratory flow is recommended for reliable capsaicin cough challenge testing in pediatric populations.