The causes of acute cough: a tertiary-care hospital study in Japan.

Objectives: Cough is the most frequent presenting complaint in general practice and has an adverse effect on an individual's well-being. Understanding the causes of cough is critical for appropriate patient management. According to its duration, cough is classified as acute, subacute, and chronic. While acute respiratory infection is considered to be the major cause of acute cough, there is little evidence.

Methods: We retrospectively assessed the prevalence of acute cough in all patients presenting with cough to the respiratory clinic of Japanese Red Cross Wakayama Medical Center from May 2018 to April 2019. We subsequently assessed the causes of acute cough, after stratifying patients with acute cough into two subgroups based on the chest X-ray findings.

Results: Among 685 patients (329 males; mean age, 61.8 ± 18.6 years) who presented with cough as a chief complaint, 274 (125 males; mean age, 57.6 ± 20.9 years) reported to have acute cough; chest X-ray abnormalities were detected in 113 of these patients. The most frequent cause of acute cough among 113 patients with chest X-ray abnormalities was pneumonia (55.8%), followed by lung cancer (9.7%) and pneumonia exacerbating asthma (7.1%). Among the 161 patients with acute cough without chest X-ray abnormalities, the most frequent cause was upper respiratory tract infection (57.1%), followed by asthma (23.6%) and cough variant asthma (6.2%).

Conclusions: Cough is the most frequent presenting complaint in general practice. Infections are the most frequent causes of acute cough regardless of the chest X-ray findings.