Abstract
Background: Upper airway cough syndrome (UACS) is generally considered the main cause of chronic cough, but it is rarely recognised in Japan. This study identified the causes of chronic cough and assessed whether “UACS is the most common cause of chronic cough” in Japan, as it is in other countries. Although signs and symptoms of UACS are described as nonspecific, some items of interviews and examinations might be considered potentially useful in its diagnosis, and were evaluated for their association with it. Methods: All patients with chronic cough who visited my clinic were preliminarily diagnosed based on interviews and examinations. Bronchial asthma and UACS were preferentially diagnosed. Among the excluded cases, some patients with gastrointestinal symptoms or diet-related cough were diagnosed with gastroesophageal reflux disease, while others were diagnosed with post-infectious prolonged cough. Nasal corticosteroids were administered to the UACS group, and standard treatment to the other groups. The observation period lasted 4 weeks. Subjective cough score at first diagnosis was set at 10, and final diagnosis was made based on the treatment administered when the cough score had decreased to ≤2. The association between the presence or absence of UACS and interview and examination items was statistically evaluated using a logistic regression model. Results: Among 230 patients with chronic cough, 146 were diagnosed with UACS-only. In the UACS-only group treated with nasal corticosteroids, 110 patients showed a significant improvement in cough scores within 2 weeks. Multivariate logistic regression revealed that assessment items “awareness of mucus accumulating in the back of the throat” (odds ratio [OR]: 4.613; 95% confidence interval [CI]: 1.124–18.928; P=0.034), “presence of abnormal echography findings” (OR: 15.725; 95% CI: 1.445–171.101; P=0.024), “absence of associated coughing when exercising” (OR: 0.212; 95% CI, 0.055–0.813; P=0.024), and “presence of coughing persisting after onset” (OR: 6.470; 95% CI, 1.755–23.843; P=0.005) were significantly associated with the presence or absence of UACS. Conclusions: UACS is the most common cause of chronic cough in Japan, as in other countries, and can be effectively treated with nasal corticosteroids. Diagnosing UACS might be possible by selecting appropriate interview and examination items.
713 Common Cause of Chronic Cough in Children
