Obstructive sleep apnea-induced chronic cough: three case reports and a review of the literature

Objective: The aim of this study was to analyze the clinical features of obstructive sleep apnea (OSA)induced chronic cough and improve the current understanding of the association between chronic cough and OSA. Methods: We used chronic cough and obstructive sleep apnea as the key words with which to retrieve relevant literature from the PubMed database from January 2002 through November 2014. Eight articles were included: four were case reports of nine patients (three male and six female patients aged 46-73 years); the other four articles were epidemiological studies of patients with concurrent OSA and chronic cough. A literature review was performed by combining the characteristics of the cases reported in the literature and the three cases in the present report. Results: Case 1 involved a 60-year-old woman with a 3-month history of cough. Case 2 involved a 52-year-old man with a 3-year history of cough. Case 3 involved a 63-year-old man with a 5-year history of cough and chest tightness. Common causes of chronic cough were excluded in these three cases. Polysomnography indicated a diagnosis of severe OSA, and the patients’ symptoms were resolved after continuous positive airway pressure therapy. Conclusions: OSA is a possible etiology of chronic cough. Chronic cough can be the sole presenting symptom in patients with OSA. The incidence of chronic cough is significantly high in patients with OSA. Continuous positive airway pressure treatment can significantly improve chronic cough.