Introduction: Prolonged or recurrent cough in children has different underlying causes, which vary across settings and age. We assessed diagnostic testing and final diagnosis given to children visiting respiratory outpatient clinics in Switzerland.

Methods: We analysed data from the multicentre Swiss Paediatric Airway cohort study. We included 363 children (median age 6 years, range 0-16, 60% male) referred for prolonged or recurrent cough. We extracted information on diagnostic investigations, final diagnoses proposed by paediatric pulmonologists, and treatment prescribed from outpatient records.

Results: Final diagnosis was asthma and asthma-like conditions in 133 (37%), respiratory tract infections (RTI) including protracted bacterial bronchitis in 50 (14%), upper airway cough syndrome (UACS) in 45 (12%), post-infectious cough in 36 (10%), and unknown or other diagnoses in 99 (27%). Among children aged < 5 years, 27% had asthma, 24% RTI, and 14% UACS while among those aged ≥ 5 years, 42% had asthma, 12% UACS and 8% RTI. Fractional exhaled nitric oxide was measured in 73%, lung function in 71%, and chest X-rays were done in 25%. Most children (83%) diagnosed with asthma were prescribed inhaled corticosteroids, alone or in combination with long-acting beta agonists, 42% of the children with RTI were prescribed antibiotics and 82% of those diagnosed with UACS were prescribed nasal corticosteroids.

Conclusion: Asthma was the most common diagnosis, in a third of the children. Final diagnoses differed strongly by age.  The cause of cough was unknown in 20% of the children, highlighting the diagnostic challenge and the need for further research to improve diagnosis of prolonged and recurrent cough.

Funding: SNSF 320030_212519