No abstract

Protracted bacterial bronchitis (PBB) is a common cause for chronic wet cough in children. Protracted bacterial bronchitis is defined by persistent productive cough in a child lasting for more than 4 weeks duration in the absence of symptoms or signs of other causes of chronic wet cough and which resolves following a 2-4-week course of an appropriate oral antibiotic. The microbiological criteria in certain situations include a positive bronchoalveolar lavage (BAL) culture. The most common organisms responsible for PBB are non-typable Hemophilus influenzae (NTHi) (47-81%), Streptococcus pneumoniae, and Moraxella catarrhalis. Human adenovirus (HAdV) is a known viral pathogen. The pathophysiology is an initial viral insult to the respiratory tract that disrupts the normal morphology and mucociliary function that leads to chronic inflammation and formation of biofilms that reduce the antibiotic penetration. Persistent neutrophilic inflammation, caused by the presence of capsulated organisms in the respiratory tract results in a loss of ciliary function, increased mucus production and bacterial stasis, resulting is a vicious cycle of chronic inflammation and infection and eventually bronchiectasis. Protracted bacterial bronchitis can be associated other chronic conditions with impaired mucociliary clearance and large airway malacias. It is most common in the preschoolers aged between 10 months and 4.8 years. These children appear generally healthy with normal growth and development and lack signs of chronic suppurative lung disease such as clubbing, chest deformities, or crepitations. A child with PBB typically presents with history of prolonged wet cough that is more at night and with postural changes. They can also present with shortness of breath and noisy breathing. The symptoms can also be aggravated with viral infections, resulting in exacerbations during these acute episodes. All these symptoms may be similar to asthma, and hence PBB is commonly misdiagnosed and treated as asthma. Chest radiography in PBB shows occasional perihilar changes due to peribronchial wall thickening. A computed tomography (CT) scan is indicated only if there is a recurrence, treatment failure, or suspicion of bronchiectasis. Flexible bronchoscopy with BAL is reserved in recurrent PBB and in those with treatment failure, as it is not easily available in most settings. Protracted bacterial bronchitis, which is not treated adequately, can predispose to bronchiectasis and chronic suppurative lung disease. Protracted bacterial bronchitis typically responds to a 2-4-week course of appropriate antibiotics. The antibiotic of choice is amoxicillin-clavulanate followed by macrolides, trimethoprim-sulfamethoxazole, or cephalosporins in select patients.