Clinical Profile of Patients with Chronic Cough, Assessment of Feno Values and Corticosteroid Responsiveness

Background: Cough is the most common symptom for which patients seek medical attention. Estimates of prevalence of cough vary, but as much as 12% of the general population report chronic coughing defined as cough lasting for more than 8 weeks. Evidence suggests that the common medical conditions associated with chronic cough are Cough Variant Asthma (CVA), Upper Airway Cough Syndrome (UACS), Non Asthmatic Eosinophilic Bronchitis (NAEB), Gastro Esophageal Reflex Cough (GERC). Materials and Methods: A retrospective observational study was conducted in the Respiratory Medicine OPD of SRMS Bareilly which included 100 patients with chronic cough, with normal radiology and normal spirometry. Relevant information related to clinical characteristics was extracted and Fractional Exhaled NO levels were obtained in patients using the portable FENO device. Based on the FENO values, the HIGH FENO group was given an ICS LABA trial of 8 weeks, and then reassessed by repeating FENO testing. Results: out of 100 patients, 58 were males, 42 were females. The mean FENO values were 47.98ppb for males and 59.00 ppb for females.61 patients fell in the HIGH FENO group with a mean FENO of 71.2 +/-44.15 while 39 people were included in the LOW FENO group with mean FENO value of 14.92+/-6.55. Higher FENO values were seen in patients with associated allergy and recurrent URTI symptoms. Chronic/ ex smokers (11%) showed a higher FENO value as compared to non smokers (65.91ppb versus 48.38ppb). In this study, there was a significant decrease in FENO value after ICS LABA trial in the HIGH FENO group (67%) Conclusion: Study showed that FENO values may be used to diagnose and phenotype patients with chronic cough, HIGH FENO group was the steroid responsive group, shown by the decreased FENO values after ICS trial.