Asthma and Sinusitis: Association and Implication

<i>Background:</i> Sinusitis occurs frequently in asthmatic patients. Epidemiologic data on sinusitis and lower airway disease must be evaluated with caution because they are based mostly on symptoms and do not include nasal endoscopic or computed tomography (CT) findings. Clinical support and evidence for this association are lacking. We evaluated the impact of sinusitis on lower airway disease in patients with well-characterized asthma. <i>Methods:</i> Subjects (n = 188) completed a questionnaire designed to provide information about their signs and symptoms related to asthma, allergic rhinitis (AR) and sinus disease. Patients (n = 104) were divided into four groups based on the presence or absence of sinusitis and/or AR. Clinical findings were compared in asthma patients with and without diagnosed sinusitis, by an otorhinolaryngologist or based on sinus CT findings. <i>Results:</i> The prevalence of sinusitis in patients with asthma was 36.7%. Sinus CT scan abnormalities were detected in 66.3% of patients with asthma. The scans revealed abnormal opacity in 17.9% of asthmatic patients without a history of sinusitis. There was a significant correlation between the rate of asthma severity and sinus morphologic abnormalities in patients with and without sinusitis. In adult-onset asthma (≧16 years old), sinusitis frequently preceded asthma, whereas in non-adult-onset asthma (<16 years old) it preceded sinusitis. The complication rate of sinusitis in asthmatic patients was significantly higher in adult-onset asthma than in non-adult-onset asthma. <i>Conclusions:</i> Our findings suggest that bronchial asthma is closely related to sinusitis and the onset age of asthma is important when considering allergic disease frequency. Whether sinus disease directly affects the intensity of bronchial inflammation remains to be elucidated.