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We write with regard to the retrospective chart review by Donnelly published recently in Thorax.1 The review covers a 5 year period and it is presented as a cross‐sectional survey of their personal practice of children with persistent bacterial bronchitis. We are unsure how often the patients were seen over the time of the review and it does not examine outcomes longitudinally.
We agree that there is a lack of clarity regarding the definition of chronic bronchitis. However, like all diagnoses of exclusion, it is a difficult diagnosis to make. The definition of chronic bronchitis in adults is more specific: “the presence of chronic productive cough for 3 months in each of two successive years and a patient under whom other causes of chronic cough have been excluded”.2 Comments regarding the diagnosis from two recently published paediatric respiratory text books are illuminating. In the first3 the adult definition of chronic bronchitis is given but “whether this definition can be applied to childhood chronic bronchitis remains unclear” and “it has the potential to divert the paediatrician from detecting a more specific respiratory condition”. The authors of the chapter suggest that: “The diagnosis of chronic bronchitis should occur in two phases. The first is consideration and identification of several well defined respiratory disorders according to a staged management protocol. The second but simultaneous phase is elimination or modification of exogenous factors that produce or maintain the child's illness.” The second paediatric text4 also notes that “the definition of chronic bronchitis in children is less clear …”.
Our concern with this paper, based on our own experience, is that the label of “chronic bronchitis” is given to children without adequate exclusion of other diagnoses. We acknowledge that our centres may differ because of the referral pattern, with most of the patients in this review from primary rather than secondary care. The definition in this article is very reliant on a persistent “wet cough”, with no other anomalies. However, in this group of 81 children, 68% had abnormal chest radiographs (of the 98% in whom they were done), but only 17% had chest CT scans and 23% underwent bronchoscopic examination. The other paper5 with which the authors align themselves had 15 patients diagnosed with chronic bronchitis, but all of these had a negative chest CT scan and all had positive bronchoscopy so a more accurate diagnosis is likely. One of the diagnostic criteria used in this article was response to antibiotics—analogous to response to asthma treatment. However, while only asthma responds to asthma treatment, many conditions may respond to antibiotic treatment and time alone may lead to some symptom resolution, so it is not a discriminating diagnostic characteristic. We agree that persistent bacterial bronchitis is often misdiagnosed as asthma although the two conditions may coexist and, although 30% of families smoked, there was no discussion on the impact this may have had.
We agree that chronic bronchitis is a real entity and that it may be underdiagnosed at the current time. Untreated, this condition may progress to bronchiectasis in an (unknown) percentage of children and prospective work in this area is needed to confirm this. However, we need to proceed cautiously so as not to miss already established bronchiectasis or other diseases without adequate investigations. It is hard to label all of these children as chronic bronchitis when 59% had symptoms for more than 1 year, 13% required six courses of 4–6 weeks of antibiotics before improvement, and so few had chest CT scans or bronchoscopic examinations. Those that improved after two courses of antibiotics with no chest radiographic changes would be understandable to label as more likely to have chronic bronchitis. In this paper, however, that would amount to 51% of the patients.
In addition, we disagree that the children with an underlying immunodeficiency frequently have bronchiectasis that resolves. The only groups in which we have seen this happen regularly are those with bronchiectasis secondary to foreign body inhalation or those diagnosed during immunosuppressive treatment for an oncological disease; other examples of reported circumstances are referenced.6,7
The authors state that most publications (not referenced) relating to idiopathic bronchiectasis focus on diagnosis and management and ignore the antecedent stages of the disease; this is not true.10,8,9 Interestingly, while both the paediatric texts cite a number of differential diagnoses that require exclusion before using the term “chronic bronchitis”, neither specifically mentions bronchiectasis although both mention cystic fibrosis, yet the former is far more common in our experience and in other populations.8,9,10,11
The diagnosis of chronic bronchitis still needs to be made with care. While we believe it is a true and often under‐recognised entity, there is still a risk of incorrectly ruling out other underlying problems which may well result in a child re‐presenting with greater lung damage at a later stage. We recognise that it remains a difficult decision between assuming chronic bronchitis or subjecting a child to the radiation of a high resolution CT scan and the possible morbidity associated with bronchoscopy. In a child with persistent wet cough for more than 4 weeks, the features we believe should indicate more aggressive ascertainment of a definitive diagnosis would be:
We agree that research and discussion need to continue in this area with regard to development of disease, diagnosis and nomenclature.