Protracted bacterial bronchitis: The last decade and the road ahead

Area of Science:

• Pediatrics
• Respiratory Medicine
• Infectious Diseases

Background:

• Chronic cough is a significant health concern in children, impacting quality of life.
• Protracted bacterial bronchitis (PBB) is a frequent cause of chronic wet cough in children under six.
• PBB is characterized by a persistent productive cough unresponsive to initial treatments, often requiring prolonged antibiotic therapy.

Purpose of the Study:

• To review the clinical presentation, diagnosis, and management of protracted bacterial bronchitis (PBB) in children.
• To explore the pathobiologic mechanisms and immune responses associated with PBB.
• To differentiate PBB from other causes of chronic wet cough, such as bronchiectasis.

Main Methods:

• Literature review of studies on childhood chronic cough and PBB.
• Analysis of clinical characteristics, diagnostic findings (including bronchoscopy and bronchoalveolar lavage), and treatment outcomes.
• Examination of immunological markers and inflammatory pathways in PBB.

Main Results:

• PBB typically presents as a chronic wet cough, often with purulent secretions and neutrophil infiltration in bronchoalveolar lavage, commonly caused by Haemophilus influenzae.
• Antibiotic treatment (e.g., amoxicillin-clavulanate) for 2-4 weeks is effective, but recurrences are common.
• Immune studies suggest activated innate immunity and increased IL-1β signaling, rather than immune deficiency, in PBB.

Conclusions:

• PBB is a distinct clinical entity treatable with antibiotics, but its high recurrence rate warrants monitoring for conditions like bronchiectasis.
• The pathogenesis of PBB involves complex inflammatory responses, with PBB and bronchiectasis potentially representing a disease spectrum.
• Further research is needed to elucidate the exact role of airway malacia and inflammatory mechanisms in PBB.