Introduction It is important that health professionals consider a list of differential diagnoses when faced with a child with chronic cough (acute cough usually lasts less than three weeks). Potential causes include: asthma, cystic fibrosis, foreign body aspiration, anatomical abnormalities of the airways and other disorders.

Studies have shown that children with chronic wet cough often have bronchitis and this is evident on bronchoscopy. Protracted bacterial bronchitis (PBB) is defined as persistence of isolated wet cough lasting more than four weeks and responding to antibiotic treatment.

Diagnosis Clinical is achieved by presence of wet cough lasting >4 weeks. It is primarily a neutrophilic disease and presence of respiratory bacterial pathogens has been demonstrated in bronchoalveolar lavage. Prolonged course of oral antibiotics of 2–3 weeks is suggested as the initial therapy. Treatment is likely to result in symptom resolution and may minimise the risk of developing bronchiectasis. Chest X-ray may be performed in some cases and will be found to be normal in most instances. Sputum culture may also be sent in older children.

Diagnosis may be confirmed by bronchoscopy with BAL followed by bacterial study; however, such an invasive approach may not be deemed necessary or may not be readily available in most cases.

Treatment The British Thoracic Society (BTS) advises using four to six weeks of oral antibiotics.4 In the absence of a bacterial culture a prolonged course of either amoxicillin or a macrolide antibiotic is suggested in most children with PBB.