Extract
We thank S. Zhong and co-workers for their interest and thoughtful letter in response to our manuscript, “The effect of pain conditioning on experimentally evoked cough: evidence of impaired endogenous inhibitory control mechanisms in refractory chronic cough” [1]. In this study we demonstrated that a painful cold stimulus, applied to the hand, inhibited cough responses to capsaicin in humans, and that this phenomenon (known as conditioned pain modulation, CPM) was impaired in patients with refractory chronic cough. Interestingly, the recent study performed by Dong et al. [2] also investigated the effects of cold on the cough reflex. They found placing guinea pigs in a cold environment had the opposite effect, heightening cough responses to cinnamaldehyde in animals repeatedly exposed to citric acid; the citric acid exposure being an attempt to emulate the hyperexcitability of the cough reflex observed in patients with chronic cough.
Abstract
Cold-induced pain inhibits cough responses to capsaicin, and this contrasts with the effect of whole-body exposure to cold environments in animal models, which heightens the cough responses to some inhaled irritants. https://bit.ly/2MiZdN2
Footnotes
Author contributions: I. Satia and J.A. Smith wrote the first draft of the manuscript. All authors reviewed the final manuscript and approved for submission.
Conflict of Interest: I. Satia reports personal fees for educational talks for GPs from GSK and AstraZeneca, grants and personal fees from Merck Canada, grant from ERS Respire 3 Marie Curie Fellowship, grant from Dept of Medicine, McMaster University (E.J. Moran Campbell Early Career Award), outside the submitted work. E. Iovoli has nothing to disclose. K. Holt has nothing to disclose. A.A. Woodcock reports personal fees for lectures from GlaxoSmithKline, personal fees for lectures and consultancy from Novartis, personal fees for consultancy from Chiesi, other (chairman; cough drug in phase 1) from Axalbion, other (chairman; food allergy diagnostics) from Reacta Biotech, other (chairman; charity owned clinical trials unit) from Medicines Evaluation Unit, outside the submitted work; and has a patent cough monitor licensed to Vitalograph. J. Belcher has nothing to disclose. J.A. Smith reports grants and personal fees for advisory board work and consultancy from GlaxoSmithKline, NeRRe Pharmaceuticals, Menlo, Bayer, Boehringer Ingleheim, Axalbion, Afferent and Merck, personal fees for consultancy from Genentech, Neomed, Bellus, Chiesi, AstraZeneca and Algernon, non-financial support (equipment provision) from Vitalograph, outside the submitted work; has a patent method for generating output data licensed.
Support statement: I. Satia is currently supported by the E.J Moran Campbell Early Career Award, Dept of Medicine, McMaster University and was previously supported by the European Respiratory Society Respire 3 Fellowship (R3201703-00122). The study was conducted with the support of the NIHR Manchester Clinical Research Facility. J.A. Smith is funded by the NIHR Manchester Biomedical Research Centre, a Wellcome Investigator in Science Award and is an NIHR Senior Investigator.
- Received January 26, 2021.
- Accepted January 27, 2021.
- Copyright ©The authors 2021. For reproduction rights and permissions contact permissions{at}ersnet.org