Introduction
cough, Behavioral cough suppression, RCC
LUNG DISEASE, RCC
Refractory chronic cough (RCC)—a cough lasting more than 8 weeks that has not responded to guideline-based interventions and is not associated with smoking or lung disease—impacts up to 7 million Americans each year [The cough reflex is a complex sensorimotor function involving interaction between peripheral and central networks [Behavioral cough suppression therapy (BCST) focuses on interoceptive cues of UTC and implemention of specific cough suppression strategies in reponse to UTC [For these reasons, we previously developed and showed preliminary evidence for a treatment approach called cough desensitization treatment (CDT), where UTC is elicited in a controlled manner in a therapeutic context to facilitate successful cough suppression. In CDT pilot 1, patients with CHS, who previously had not responded to BCST, were exposed to progressive doses of inhaled aerosolized capsaicin via a nebulizer and coached to suppress cough [The purpose of the current study was to expand on this work with a refined protocol given what was learned from pilot 1. Protocol modifications included: (1) a dose increase to 12 sessions, (2) additional validated outcome measures including cough-reflex sensitivity and a visual-analogue scale of cough severity, (3) revised sham treatment, and (4) expansion of inclusion criteria to include patients with RCC who had not yet received BCST. We hypothesized CDT would result in significantly improved outcomes and a reduction in cough-reflex sensitivity relative to sham treatment. The trial (NCT05226299) was registered on Clinicaltrials.gov on 07/02/2022.