Based on emerging new evidence and expert consensus, an international panel selected by the American College of Chest Physicians released recommendations for the noninvasive measurement of airway inflammation and management of cough due to asthma or nonasthmatic eosinophilic bronchitis (NAEB). This report was published in CHEST.
The CHEST Expert Cough panel performed a systematic review of studies focused on the assessment and treatment of persistent cough in patients with asthma and NAEB using methods involving noninvasive markers. The panel developed 4 recommendations following a modified Delphi technique in which they devised 3 related questions, elicited feedback, and reached consensus through an anonymous survey.
Despite the large amount of high-quality evidence available for guiding treatment of asthma overall, the panel noted that the findings of their review reflected the lack of good quality trials on the role of noninvasive measures of airway inflammation and treatment for chronic cough in asthma and NAEB. Future studies should include objective measures of cough to understand the effect of asthma therapies on cough.
Recommendations for Measuring Airway Inflammation
The panel recommended noninvasive methods of assessing airway inflammation in patients with chronic cough associated with asthma, including measuring inflammatory markers such as blood or sputum eosinophil counts and fractional exhaled nitric oxide. Markers demonstrating the presence of eosinophilic airway inflammation were shown to predict a more favorable response to inhaled corticosteroids (ICS; Evidence Grade 2B).
Recommendations for Treatment of Cough Variant Asthma
In patients with asthma where chronic cough occurs as a unique symptom, otherwise known as cough variant asthma, the panel recommended ICS as first-line treatment. If the response to first-line therapy is incomplete or if cough is the remaining isolated symptom following treatment with ICS, the panel recommended stepping up the ICS dose and considering a therapeutic trial of leukotriene receptor agonists. Inhaled beta-agonists in combination with ICS may be considered in combination with ICS (Evidence Grade 1B).
Recommendations for Treatment of Cough Due to NAEB
In patients who present with chronic cough due to NAEB, the panel recommended ICS as first-line treatment in which beneficial improvements in cough were consistently observed in response to corticosteroid treatment in all included trials comparing ICS with placebo (Evidence Grade 2B). However, because there are few trials in NAEB and all include small populations, the panel noted that this should be considered a weak recommendation.
Recommendations for Incomplete Response to Corticosteroids in NAEB
If patients with chronic cough due to NAEB experience an incomplete response to ICS therapy, the panel recommended stepping up the ICS dose. If the treatment continues to fail to elicit a response, patients should be assessed for alternative causes of cough and a therapeutic trial of leukotriene receptor agonists can begin (Evidence Grade 2C).
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a complete list of authors’ disclosures.
Côté A, Russell RJ, Boulder LP, et al; on behalf of the CHEST Expert Cough Panel. Managing chronic cough due to asthma and NAEB in adults and adolescents: CHEST guideline and expert panel report [published online January 20, 2020]. CHEST. doi:10.1016/j.chest.2019.12.021