Dear Sir,
We thank the author for highlighting that endobronchial tuberculosis (EBTB) can be a cause of chronic cough.(1) We do recognise that EBTB is one of the uncommon manifestations of pulmonary tuberculosis in Singapore, can present as chronic cough and can occasionally have normal chest radiograph findings.
While it is possible that an EBTB patient can present with isolated cough as the primary symptom (with no other alarming symptoms such as weight loss, fever, haemoptysis or dyspnoea) and also have a normal chest radiograph, we feel that this is an uncommon occurrence. In our unpublished data bank of 300 patients referred to the respiratory clinic at Changi General Hospital, Singapore, for workup of chronic cough, only one patient was eventually diagnosed with pulmonary tuberculosis. Although this patient had weight loss and infiltrates on chest radiography, the referring general practitioner was not convinced and referred the case for workup of cough. While it is possible that a diagnosis of EBTB was missed in some of these referred cases, we think this is unlikely. It should be mentioned that the vast majority of cases referred to us had normal chest radiographs and no alarming signs.
As mentioned at the start of our article, primary care physicians were the main target readers, and our discussion focused on patients who had only cough as the primary symptom, with a normal chest radiograph.(2) Like other articles in the Singapore Medical Journal ’s Practice Integration and Lifelong Learning Series, our paper was meant to be a short overview of a topic, integrating knowledge across the practice for the benefit of primary care physicians. Hence, we only covered the common causes of chronic cough without intending to provide an exhaustive list of all the causes.
Yours sincerely,