Investigation of Filamentous Basidiomycetes in the Airway Is the Third Unmet Need in the Management of Unexplained Chronic Cough in Adults.

Dear Editor, Managing unexplained chronic cough (UCC) is still an important issue even among cough specialists. Irwin et al. [1] commented on two clinical needs that must be met to improve quality of life in patients with UCC: the development of new therapies and the need for clinicians to practice intervention fidelity by adhering to best clinical practice guidelines for chronic cough. Here, we discuss a third unmet need related to environmental assessment, which should be included in “further investigation to consider” described in the clinical practice guidelines for chronic cough [2]. Although filamentous basidiomycetes (f-BM), environmental fungi, are not generally detected in airway specimens of respiratory health patients, f-BM colonization in the airway mucosa of chronic cough patients has been recognized as an exacerbation factor of cough symptoms [3]. Airway mucus plugs, recently reported to exacerbate asthma, have also been detected in the peripheral airways of patients with chronic cough with f-BM colonization [4]. The relation between f-BM colonization and mucus plug formation in the airway is an important concern. Received: May 5, 2020 Accepted: May 12, 2020 Published online: August 5, 2020