• Paediatric Lung Disaese

Most healthy children shrug off viral respiratory tract infections with little difficulty or assistance and a full recovery is the norm. A small minority, in contrast, are left with serious consequences. Important among these is postinfectious bronchiolitis obliterans (pBO) characterised by persistent—and sometimes severe—airway obstruction with functional and radiological evidence of small airway involvement that is generally unresponsive to bronchodilator or steroid treatment. Diagnosis is usually confirmed by high resolution computed tomography scanning although the images can be confused with asthma1 and clinical context is everything. Lung biopsy is rarely needed, but if it is done, fibrosis and obliteration of the distal airways are the cardinal features. Treatment options are limited and proof of their effectiveness largely anecdotal; there are no relevant randomised controlled trials but asthma therapies, including bronchodilators, and long term azithromycin are often used. Supportive care should be offered, with oxygen as needed, avoidance of indoor and outdoor pollution, especially tobacco smoke, immunisations including pneumococcal and influenza, and good nutrition.

In most settings, pBO is undoubtedly rare but in the absence of systematic case registration its incidence is unmeasured. While cases have been reported in many different countries, there has been, for around 30 years, a striking preponderance from the southern ‘cone’ of South America (Chile, Argentina and southern Brazil) where the condition seems to have been more common than elsewhere. For example, 28% of 415 children admitted with an acute lower respiratory infection over a 17-year period to a hospital in Buenos Aires developed pBO (a further 15% died) over an unquantified period of observation. …