• Respiratory
• Microbiology

Protracted bacterial bronchitis (PBB) is increasingly recognised as a cause of chronic cough in children.1 It is characterised by bacterial infection of the conducting airways that produces an antibiotic responsive wet cough.2 At our centre, children with suspected PBB are treated empirically with a 2-week course of amoxicillin/clavulanic acid. If they do not respond or their symptoms relapse, then flexible bronchoscopy with bronchoalveolar lavage (FB-BAL) is undertaken to obtain a microbiological diagnosis. In those whom PBB is confirmed, a prolonged course of an appropriate antibiotic is prescribed. There are relatively little data available on response to treatment, but it was our experience a high percentage of children were experiencing relapses of their wet cough after initial treatment. We therefore undertook a retrospective review of treatment outcomes for children with PBB between 2011 and 2013. To minimise ambiguity about the diagnosis, we only included children with a clinical diagnosis of PBB (antibiotic responsive wet cough) that had been confirmed by a positive BAL culture.

Forty-four children were included with a median (IQR) age of 2.7 (1.5–4.0) years. The median (IQR) duration of cough prior to FB-BAL was 11.0 (9.0–14.7) months and the duration of data collection was 11.3 (8.3–14.7) months. Twenty-one of these forty-four children (48%) isolated ≥2 different organisms from BAL cultures. The commonest organisms were Haemophilus influenzae (n=27), Moraxella catarrhalis (n=22), Streptococcus pneumoniae (n=10) and Staphylococcus aureus (n=8). All children received a 6–8 week course of oral antibiotics. The majority (27/44) received amoxicillin/clavulanic acid, but flucloxacillin or clarithromycin was prescribed when S. aureus was isolated and amoxicillin was prescribed when a sensitive H. influenzae or S. pneumoniae was isolated. Follow-up data were not available for one child. In 33/43 (77%), the initial antibiotic course produced complete resolution of the cough, but only eight (24%) of these remained cough free. All 25 children whose cough recurred received further treatment courses of antibiotics (duration 2–6 weeks), nine were subsequently started on prophylactic antibiotics and two were investigated for an alternative diagnosis (see figure 1). Ten children had improvement but not resolution of their cough with the initial course of antibiotic; three of these received further courses of antibiotics, four were subsequently started on prophylactic antibiotics and three were investigated further for an alternative diagnosis. Amoxicillin/clavulanic acid was used in all 13 children commenced on a prophylactic antibiotic. Of the five children investigated for an alternative diagnosis, three were diagnosed with asthma and commenced on inhaled corticosteroids. No cause was identified in the remaining two children.

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Figure 1

Flow chart of treatment outcomes in 44 children with protracted bacterial bronchitis (PBB) confirmed by bronchoalveolar lavage culture.

This is the first long-term review of treatment outcomes in children with PBB confirmed by FB-BAL. A previous review of 81 children with a clinical diagnosis of PBB (only a minority had FB-BAL) found that 41 (51%) of children were symptom free after two courses of antibiotics, but 11 (13%) required ≥6 treatment courses or prophylactic antibiotics.3 In another study, FB-BAL was undertaken in 102 children with chronic cough and when indicated antibiotics were prescribed. This treatment only resulted in resolution of cough in 36 (35%) children, but it is not clear how many of the initial cohort had PBB.2 The data from this study confirm that the majority of children with PBB confirmed by FB-BAL will have complete resolution of their wet cough with a prolonged course of antibiotics. Unfortunately, most will relapse and require further treatment courses or prophylactic antibiotics.