Figure 3. Algorithm for evaluation of chronic cough. ^*When clinical manifestation is suspicious for UACS, empirical treatment can be tried even if PNS X-ray is normal. ^†Empirical treatment can be considered when evaluation is not feasible. ACEI: angiotensin converting enzyme inhibitor; PND: postnasal drip; PNS: paranasal sinus; UACS: upper airway cough syndrome; PFT: pulmonary function test; BDR: bronchodilator response; CVA: cough variant asthma; EB: eosinophilic bronchitis; GERD: gastroesophageal reflux disease; CT: computed tomography.