A chronic neutrophil dominated bronchitis also known variously as PBB and CSLD is relatively common in childhood. There are numerous risk factors that may contribute to the development of a chronic bronchitis [inc viral LRTIs, malacia, aspiration, poorly controlled asthma etc.]. In most cases a specific significant on-going risk factor such as CF is not identified. It is under-diagnosed due to lack of awareness (if you do not know something exists you will never diagnose it). It is commonly mis-diagnosed as 'asthma' or 'recurrent chest infections'. Diagnosis is based on pattern recognition and response to treatment analogous to accurate diagnosis of asthma. Response to treatment must be dramatic and unequivocal to make a definite diagnosis. Beware regression to the mean PBB is a biofilm disease leading to challenges in treatment. A PBB is the cause of most cases of 'bronchiectasis'. Bronchiectasis is a radiological or pathological appearance, not a disease. Most cases are curable in the absence of a major underlying risk factor such as cystic fibrosis, PCD or significant immunodeficiency. Hence bronchiectasis is a largely preventable radiological appearance.

Studies about primary spontaneous pneumothorax (PSP) in pediatric patients are not as many as in adult patients since the incidence of PSP is lower in children than in adults. There are evidence-based guidelines for the management of PSP in adults, whereas, in children, the approach of PSP is mainly extrapolated from the adult guideline. In this article, aspects of incidence rate, epidemiology, and pathophysiology, diagnosis, management, and recurrence rate about pediatric PSP are discussed.

Aim: The aim of the study was to evaluate the correlation between the 6-min walk test (6MWT) and the cardiopulmonary exercise test (CPET) in Chinese pediatric patients. Methods: A retrospective review was undertaken for Chinese patients with exercise intolerance who had undergone both 6MWT and CPET on the same day over 21 months. Pearson's correlation analysis was used to examine the correlation between the 6-min walk distance (6MWD) and the maximum oxygen uptake (VO2 _max). The 6MWD was defined as abnormal if <10^th percentile of height-matched reference, and the VO2 _maxwas defined as abnormal if <80% predicted. Results: Twenty-nine patients with a mean age of 14.3 ± 3.6 years were included in the study. The correlation coefficient (r) between the 6MWD and the VO2 _maxwas 0.457 with P = 0.013. Twenty-six (three excluded as no reference for VO2 _maxwas available for age <10 years) patients were analyzed. Using CPET as the gold standard for functional exercise capacity, 6MWT had a positive predictive value (PPV) of 92%, negative predictive value of 29%, sensitivity of 52%, specificity of 80%, and accuracy of 58% for assessing exercise capacity. Conclusion: 6MWT had a high PPV for abnormal CPET. It could still be used as a simple tool to evaluate patients with exercise intolerance.