Abstract
Tobacco smoke exposure of children is common, and is important as both a cause and/or an exacerbating factor of most respiratory diseases of children. A recent study of children at a public hospital in San Francisco, CA, found that 55% of infants and young children had biological evidence of tobacco smoke exposure. 1 Tobacco dependence starts in childhood, with close to 90% of adult smokers having started before 18 years of age. In this issue, continuing our Special Focus on Tobacco, Dr. DiFranza reviews new understandings on the development of tobacco dependence. 2 He reports that new research contradicts the traditional belief that physically dependent smokers had to maintain nicotine in the brain and that progression of smoking from intermittent to daily smoking was driven by the pursuit of pleasure. He describes the rapidity with which tobacco dependence develops in adolescents, that daily smoking is not a prerequisite to dependence, and that latency to withdrawal drives the progression from intermittent to daily smoking. He describes the withdrawal process progressing through three levels of intensity: wanting, craving, and needing. Understanding how tobacco dependence develops is important for developing effective counseling and treatment strategies.
Asthma and obesity are – so to speak – joined at the hip. They are both very important public health problems, are increasingly common in the developed world, and appear to travel together—asthma is more common in the obese. In his comprehensive review article, Dr. Lang explores mechanisms that connect asthma and obesity and its implications for treatment. 3
Improving skills and changing behaviors are important parts of effective asthma management. Traditional methods for teaching knowledge and skills include in-person communication and use of printed materials. However, the technology of communication has changed. Ink is almost a thing of the past. Communication is evolving to Internet based, with extensive use of mobile technologies and social media. Research on asthma education, however, has not kept up with the rapidly changing communication technologies. In this issue, Mosniam et al. review the published studies on the use of Internet or mobile-device platforms to improve asthma knowledge and outcomes. She notes that in general these technologies were well received and have potential to reach populations that the medical community often finds difficult to reach. 4 Although still in its infancy, as Dr. Mosniam highlights, the use of technology for asthma education holds great promise.
ADAM33 gene polymorphisms are thought to be important in the development of asthma, 5 although accounting for ancestry may be important in unraveling the complex genetic architecture of asthma. 6 In this issue, Bora et al. examine associations between ADAM33 gene polymorphisms and asthma in a case control study of Turkish children. The cases had documented asthma with a history of wheezing and bronchodilator reactivity. The controls had no respiratory symptoms and no personal or family history of allergies or asthma. They did not find any significant associations between ADAM 33 polymorphisms and asthma in their sample. 7 Although it is possible that their study of 198 individuals was underpowered to detect small differences, these findings highlight the importance of studying ethnically and geographically diverse populations in investigating the genetic heterogeneity of asthma.
Fractional exhaled nitric oxide (FeNO) levels are associated with poorly controlled asthma in infants and children, and are believed to be a proxy measure of eosinophilic inflammation in the airways. 8 In this issue, Peña Zarza et al. evaluate FeNO in infants presenting to the emergency department with respiratory syncytial virus (RSV) bronchiolitis and compare them to a control group hospitalized for non-respiratory problems. Preterm infants with gestation <35 weeks and those with previous history of wheezing illness or asthma treatment were excluded. In this small study, the FeNO values between cases and controls were quite similar, although there were two outliers in the bronchiolitis with wheezing group who appeared to have substantially higher FeNO values than the others. 9 This study is important in that it documents the lack of value of FeNO in assessment of the acute phase of bronchiolitis. The findings are also provocative—does FeNO measurement of infants presenting with RSV bronchiolitis identify a subgroup at increased risk for later wheezing? We eagerly await the results of future studies to provide the answer.
The hygiene hypothesis, that early life microbial exposures are protective, has been proposed as a mechanism to explain the rising prevalence of asthma and allergy in the developed world. 10 In this issue, Lighter-Fisher and Peng use the National Health and Nutrition Survey 1999–2000 data where a subsample of 9,282 individuals underwent tuberculin skin testing. A positive tuberculin skin test in the absence of evidence of prior Bacille Calmette-Guérin (BCG) vaccination indicates a history of latent tuberculosis infection. This study found that children with latent tuberculosis infection had substantially lower risk for asthma or symptoms of asthma over the prior year than children with a negative tuberculin skin test. 11 This study is important for two reasons. First, it provides additional evidence in support of the hygiene hypothesis. Second, it demonstrates that substantial value can be obtained in secondary analyses of existing high quality data sets. Making use of existing data sets to yield new insights is important. Large, representative, high quality data sets with rigorously collected data take substantial effort and cost to assemble. Making good use of them is simply being good stewards of the resources that the public gives to us.
Although much effort goes into creating new, expensive, high technology assessment instruments, it is refreshing to see new applications of older, simpler, and less expensive assessment methods. Pulmonary exacerbations of Cystic Fibrosis are common reasons for hospitalization and are associated with deterioration of lung function and health status. In this issue, Bhatia et al. explore the implications of changes in 6-minute walk test (6MWT) during hospitalization for a pulmonary exacerbation of Cystic Fibrosis on health-related quality of life. It is not just that patients are better—but it is also important that they feel better. They found that changes in 6MWT did not correlate with changes in lung function measures (although both tended to improve). Rather, the change in 6MWT (but not changes in lung function) correlated with changes in the physical domain of the Health-Related Quality of Life Cystic Fibrosis Questionnaire—Revised score. 12 Perhaps lung function is not everything.
We hope that you find this issue of Pediatric Allergy, Immunology, and Pulmonology interesting and stimulating. Your contributions to this journal are valued. You can find instructions for authors online at www.liebertpub.com/manuscript/pediatric-allergy-immunology-and-pulmonology/48/.