Mapping Cough Receptors in the Larynx and Pharynx in Healthy Individuals: A Scoping Review

PURPOSE: The purpose of this study was to identify and describe extrapulmonary cough receptors located in healthy individuals' larynges and pharynges and the types of stimuli to which they are sensitive. METHOD: This scoping review was registered in the Open Science Framework. The review followed the Joanna Briggs Institute methodology and was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews. The search was performed electronically in the LILACS, Scopus, manually in gray literature (Google Scholar, MedRxiv, and ProQuest), and by mapping citations and consulting experts. The search was initiated in August 2024. The review included primary studies describing laryngeal and/or pharyngeal cough receptors in healthy human individuals. The data were analyzed descriptively. RESULTS: The search found 12 studies on extrapulmonary cough receptors, all describing laryngeal and seven of them also pharyngeal ones. Only rapidly adapting receptors (RARs) with myelinated fibers were reported in both regions, responding predominantly to mechanical stimuli. The locations of the receptors, when described, are not uniform, with epithelium and mucosa being possible sites. CONCLUSIONS: Data on the location of extrapulmonary cough receptors in healthy individuals are heterogeneous. RARs that respond mainly to mechanical stimuli predominate in these regions and conduct stimuli to the nerve centers through myelinated fibers to trigger cough. However, the small number of included studies and variability in anatomical descriptions limit definitive conclusions.