ObjectiveUntreated protracted bacterial bronchitis (PBB), a chronic wet cough prevalent in children, may lead to chronic suppurative lung disease. However, clinical diagnostic criteria are currently nonspecific; thus, PBB may be misdiagnosed. Thus, we assessed the diagnostic value of fiberoptic bronchoscopy (FOB) and the risk factors associated with PBB.MethodsChildren with chronic cough at The First Affiliated Hospital of Anhui Medical University from January 2015 to May 2020 were enrolled and allocated to a suspected PBB (n= 141) or a non-PBB (n= 206) group. All children underwent extensive laboratory, chest imaging, and allergen tests. Children with suspected PBB underwent FOB with bronchoalveolar lavage; lavage and sputum samples were cultured.ResultsAll 347 children had a chronic wet cough for approximately 2 months. Of 141 children with suspected PBB, 140 received FOB with bronchoalveolar lavage. Visible tracheal changes included pale mucosa, mucosal congestion, edema, swelling, and increased secretions attached to the wall. Sputum was visible primarily in the left main bronchus (78.7%), left lower lobe (59.6%), right upper lobe (62.4%), and right lower lobe (64.5%). Sputum properties and amounts significantly differed between children with vs. without PBB (P< 0.05). Dermatophagoides (odds ratio (OR), 2.642; 95% CI, 1.283–5.369), milk protein (OR, 2.452; 95% CI, 1.243–4.836) allergies, and eczema (OR, 1.763; 95% CI, 1.011–3.075) were risk factors significantly associated with PBB.ConclusionDermatophagoides, milk protein, and eczema were associated with an increased risk of PBB. Sputum distribution and tracheal wall changes observed through FOB may distinguish PBB and assist in its diagnosis.