Diagnostic Approach to Chronic Cough

Initial Diagnostic Steps

Chest radiography is recommended by numerous pulmonary and thoracic societies as the first-line imaging test for chronic cough evaluation 1, 2
The American College of Chest Physicians (ACCP) explicitly includes chest radiography in their chronic cough algorithm 1
Initial chest radiography has shown clinical efficacy with diagnosis achieved in 82-93% of cases when used as part of standardized clinical protocols 2
Evaluate for the most common causes of chronic cough, which include upper airway cough syndrome (UACS)/post-nasal drip, asthma, and gastroesophageal reflux disease (GERD) 3

High-Resolution CT (HRCT) should be performed only in selected patients with abnormal chest radiographs or when initial evaluation and empiric treatment fail 5, 6, 7
Studies show that wide application of chest CT in all patients with chronic cough may be of low clinical yield 5, 6
Chest CT has shown positive predictive value of 90% when used in patients with suspected underlying pulmonary disease 6
Most common CT findings in chronic cough with normal radiographs are bronchiectasis (28%) and bronchial wall thickening (21%) 8

The American College of Chest Physicians recommends considering red flags such as hemoptysis, smoker >45 years with new cough or change in cough pattern, prominent dyspnea, hoarseness, systemic symptoms, and trouble swallowing, vomiting, or recurrent pneumonia for more urgent/extensive evaluation 4
Chest radiography has limitations in detecting certain conditions like bronchiectasis, with studies showing up to 34% of CT-proven bronchiectasis cases had unremarkable chest radiographs 8