Primary study objective: To determine the appropriate role and timing of sinus imaging studies in the evaluation and treatment of chronic cough.
Design: Prospective study of chronic cough. All patients underwent sinus imaging, the results of which identified prospectively the following: (1) fluid in sinuses, with or without opacification, and (2) mucosal thickening. Patients then were treated using an algorithm that sequentially addresses the etiologies of chronic cough. Patients whose sinus imaging studies had demonstrated fluid were treated initially for sinusitis, but mucosal abnormalities alone were not considered an indication to change the algorithm. After workup, relationships between abnormalities on sinus imaging studies and diagnoses were determined.
Setting: University hospital pulmonary outpatient clinic.
Patients: Thirty-six patients (31 women, 5 men; mean age, 58.4 years). Cough duration averaged 5.2 years (range, 4 weeks to 30 years).
Results: Diagnoses were made in 100% of patients, and cough resolved in 86%. Mucosal thickening correlated with sinusitis as a cause of cough in only 29% of cases.
Conclusions: Mucosal thickening is not diagnostic of sinusitis as a cause of chronic cough; in most patients, cough will resolve without treatment for sinusitis. Given this lack of specificity, it is reasonable to delay sinus imaging until after efforts at treating rhinitis have failed and, in the absence of complaint or findings of postnasal drip, until after completion of evaluation for asthma. The principles of diagnosis and treatment of chronic cough remain simple: go sequentially from the most common to the least common cause; use tools that begin with the most available and least expensive and invasive modality; then move as needed to tools that are more expensive and invasive.