Clinical features of the urge-to-cough in patients with chronic cough.

BACKGROUND

The urge-to-cough is a consciously perceived compulsion, previously investigated in healthy volunteers inhaling irritants. We aimed to characterise the urge-to-cough and associated sensations in a group of chronic cough patients attending a specialist clinic.

METHODS

100 patients with chronic cough [mean age 60 yrs (±11.89), 71 female, median cough duration 7 yrs (IQR 11.13) completed an investigator-led survey describing aggravating and relieving factors for urge-to-cough, associated somatic sensations (quality, location, intensity) and emotions. Subjects rated each using a 5-point Likert scale (strongly disagree to strongly agree) or visual analogue scale (VAS). Cluster analysis identified groups of patients with similar patterns of responses.

RESULTS

Subjects rated the severity of urge-to-cough highly (84.5 mm on VAS). The majority always cough in response to the urge-to-cough (91%), but fewer (69%) always experienced an urge-to-cough before coughing. The somatic sensations associated with the urge-to-cough were described as an irritation (86%) or tickle (73%), localised in the neck (75%). The urge-to-cough was triggered by various stimuli including smoky atmospheres (79%), talking (72%), cold temperatures (67%) and dry atmospheres (66%) and relieved by coughing (63%), and drinking (61%); in 42% nothing provided relief. Cluster analysis suggested two distinct patient groups, differing in the factors precipitating the urge-to-cough rather than quality or location of associated sensations.

CONCLUSION

The unifying characteristics of patients with chronic cough are a severe urge-to-cough associated with throat irritation, consistent with sensory neuronal dysfunction of vagal afferents. Precipitants of the urge-to-cough vary though, and can be used to classify sub-groups of patients who may share similar underlying pathophysiology.