Noxious cold stimulation: pro–con perspectives on the hypothermic effect on experimentally evoked cough

We read with great interest in the recent article by Hilton et al. [1] published in the European Respiratory Journal , about the effect of pain conditioning on experimentally evoked cough; the hypothesis and protocol are well thought out. The study showed that noxious cold-water-induced pain significantly reduced capsaicin-evoked cough; however, it was less effective in refractory chronic cough (RCC) patients than healthy volunteers. The results indicated that endogenous inhibitory control mechanisms, especially those activated by noxious stimuli-inducing pain (conditioned pain modulation, CPM), can modulate cough response evoked by capsaicin. Impairment of such mechanisms may contribute to persistent coughing in RCC patients. The cold stimulation effect on the body may have bidirectional influences on cough response in differential exposure temperature and areas