Capsaicin inhalation cough challenge

Capsaicin, the pungent extract of hot pepper, is a compound of the vanilloid class. Capsaicin induces cough in animals and man by stimulation of sensory receptors within the airways. The specific role and relative contribution of the two types of afferent fibers relevant to cough, the bronchial C-fibers and rapidly adapting pulmonary stretch receptors (RARs), remain controversial (1,2). The recent discovery of the “capsaicin receptor,” the type 1 vanilloid receptor (VR1), will likely allow further elucidation of the mechanism of action of capsaicin (3).