Diagnosis in Children With Prolonged or Recurrent Cough: Findings from the Swiss Paediatric Airway Cohort

This study specifically wanted to better elucidate etiologies for prolonged cough or cough lasting more than 4 weeks in a multicenter pediatric cohort to better determine etiologies by age enabling diagnostic evaluation and treatments outside of consideration for asthma.Using the Swiss Paediatric Airway Cohort (SPAC), this study analyzed 363 pediatric patients (16% of the cohort) from 2017 to 2022 for etiologies for prolonged/protracted or recurrent cough as their initial presentations. The SPAC is a prospective observational national multicenter cohort with 2206 children (0–16 years of life) enrolled in 10 locations in Switzerland. Inclusion was kept broad based on a loose definition of chronic/protracted/recurrent cough as their primary referral indication. Patients were excluded if they had confirmed asthma diagnosis to better determine initial investigations or diagnostic process. Of the 363 patients analyzed, 60% were male and 36% had parental tobacco exposure. Patients were stratified by age for preschool (<5 years), with 131 children vs 232 school-aged (>5 years) children.Patient- and parent-reported baseline questionnaires were obtained during encounters including respiratory symptoms and comorbidities. Attendings’ letters were reviewed, extracting the diagnostic investigation that were performed (pulmonary function testing, allergy tests, nitric oxide, sweat chloride, radiographic evaluation), diagnosis, and treatments. Final diagnoses were grouped as (1) asthma and asthma-like conditions (cough variant asthma, episodic viral wheeze, and recurrent obstructive bronchitis); (2) nonspecific postinfectious cough; (3) respiratory tract infections (RTI) including protracted bacterial bronchitis (PBB); (4) upper airway cough syndrome (UACS); and (5) unknown or other including gastrointestinal reflux disease and somatic or tic cough.One hundred thirty-two patients (36%) were found to have asthma or asthma-like etiologies, 51 (14%) had RTI with PBB diagnosed in 7%, and 48 (13%) had UACS. For the 232 school-aged children analyzed, 90 (39%) were diagnosed with asthma, UACS in 29 (13%), postinfectious cough in 22 (9%), and RTI in 18 (8%). In the 131 preschool children, 33 (25%) had RTI, with PBB making up half of those diagnoses, and 20 (15%) were diagnosed with asthma-like conditions. Historical clues in the description of the cough (wet vs dry) and timing (daytime vs nighttime) were keys in diagnosis. Between 72% and 77% of patients had cough with activity regardless of final diagnosis. Asthma had a higher association with aeroallergen trigger and history of wheeze in 43%. The most common diagnostic tests performed were fraction of exhaled nitric oxide (73%), spirometry (71%), and allergy tests (70%). For treatments, 216 (60%) were prescribed short-acting beta-agonists, 111 of the 132 patients (84%) diagnosed with asthma were prescribed inhaled corticosteroids, and 81% of the patients with infectious etiologies were prescribed antibiotics. For UACS, 83% of patients were prescribed intranasal corticosteroids.Etiologies for chronic cough vary by age, with preschool-aged children more often having postinfection etiologies or protracted infectious etiologies more commonly with dry nighttime cough vs wet sounding, respectfully. Asthma or asthma-like diagnoses occurred at a much higher rate in school-aged children. There were challenges in each age separating chronic (persistent cough greater than 4 weeks continuously) and recurrent symptoms, which warranted further study. The diagnostic algorithm varied too much to create specific recommendations. Treatment was based on diagnosis but involved more than just treating with inhaled pharmacotherapy.Although prolonged and recurrent cough remain common chief concerns to pediatricians, allergists, and pulmonary specialists, history taking and targeted diagnostic testing modalities, including pulmonary function testing and allergy tests, are often the most important ways to reach a diagnosis. Thoughtful diagnosis with considerations for other causes are important, and asthma should not be the only etiology considered. Treatment should be tailored to the presentation. This observation study laid the framework for the importance of the standardization of the diagnostic workup in these age ranges for better clinical management recommendations.