Cough Sensitivity in Pure Cough Variant Asthma Elicited Using Continuous Capsaicin Inhalation

Abstract

The cough sensitivity of patients with cough variant asthma is not necessarily identical to that of healthy individuals.

Cough Reflex Sensitivity Testing in Asthmatic Patients and Healthy Volunteers

“…We conclude that airway afferent nerve endings reactivity in asthmatic subjects was significantly increased compared with healthy volunteers. Our data about increased CRS in asthmatics are consistent with data of other studies (10,12).…”

“…Patients with asthma have an increased sensitivity to capsaicin which is most marked in those who complain of cough (10). Nakajima et al (12) showed that in asthmatics in whom cough is the sole or predominant symptom, CRS is significantly enhanced.…”

“…This dose was repeated to ensure that a reproducible C5 response had been attained and, if so, that the value was recorded as the patient's value (C5 capsaicin). In the study of Nakajima et al (12) was used continuous capsaicin inhalation (1 minute) at each concentration of capsaicin and they compared the results with those obtained using intermittent inhalation. Data showed that the threshold was significantly lower in asthmatic patients than in healthy individuals.…”

“…In the study of Doherty et al (10) CRS was independent of the degree of airway obstruction. Airway hyperresponsiveness and cough sensitivity arise through different mechanisms (12).…”

Transient Receptor Potential Channels as Drug Targets: From the Science of Basic Research to the Art of Medicine

“…For instance, inhaled capsaicin provokes exaggerated cough response in patients with cough variant, but not classic, asthma ( Fig. 31B; Nakajima et al, 2006), as well as in sensory airway hyper-reactivity syndrome (SHR) (Ternesten-Hassèus et al, 2013). Indeed, the capsaicin inhalation test is broadly used as a diagnostic tool to identify patients with SHR (Johansson et al, 2002).…”