<p>Introduction: Environmental factors play a critical role in the progression or resolution of chronic respiratory diseases. However, studies are limited on the impact of environmental risk factors on individuals born prematurely with lung disease after they leave the neonatal intensive care unit and are discharged into the home environment. Areas covered: In this review, we cover current knowledge of environmental exposures that impact outcomes of preterm respiratory disease, including air pollution, infections, and disparities. The limited data do suggest that certain exposures should be avoided and there are potential preventative strategies for other exposures. There is a need for additional research outside the neonatal intensive care unit that focuses on individual and community-level factors that affect long-term outcomes. Expert opinion: Preterm respiratory disease can impose a significant burden on infants, children, and young adults born prematurely, but may improve for many individuals over time. In this review, we outline the exposures that may potentially hasten, delay, or prevent resolution of lung injury in preterm children.</p>

<p><strong>OBJECTIVES: </strong>To study the demographic and clinical characteristics of preterm infants with bronchopulmonary dysplasia (BPD) to identify the factors most strongly predictive of outpatient mortality, with the goal of identifying those individuals at greatest risk.</p>

<p><strong>STUDY DESIGN: </strong>Demographic and clinical characteristics were retrospectively reviewed for 862 subjects recruited from an outpatient BPD clinic. Characteristics of the deceased and living participants were compared using nonparametric analysis. Regression analysis was performed to identify factors associated with mortality.</p>

<p><strong>RESULTS: </strong>Of the 862 subjects, 13 (1.5%) died during follow-up, for an overall mortality rate of approximately 15.1 deaths per 1000 subjects. Two patients died in the postneonatal period (annual mortality incidence, 369.9 per 100 000), 9 died between age 1 and 4&nbsp;years (annual mortality incidence, 310.2 per 100 000), and 2 died between age of 5 and 14&nbsp;years (annual mortality incidence, 71.4 per 100 000). After adjusting for gestational age and BPD severity, mortality was found to be associated with the amount of supplemental oxygen required at discharge from the neonatal intensive care unit (adjusted hazard ratio [aHR], 4.10; P&nbsp;=&nbsp;.001), presence of a gastrostomy tube (aHR, 8.13; P&nbsp;=&nbsp;.012), and presence of a cerebrospinal fluid (CSF) shunt (aHR, 4.31; P&nbsp;=&nbsp;.021).</p>

<p><strong>CONCLUSIONS: </strong>The incidence of mortality among preterm infants with BPD is substantially higher than that seen in the general population. The need for greater amounts of home supplemental oxygen and the presence of a gastrostomy tube or CSF shunt were associated with an increased risk of postdischarge mortality. Future studies should focus on clarifying risk factors for the development of severe disease to allow for early identification and treatment of those at highest risk.</p>

<p><strong>INTRODUCTION: </strong>Infants born prematurely are at high risk for morbidities, including lung disease (bronchopulmonary dysplasia [BPD]). Little is known regarding environmental factors that can impact outcomes in BPD. We sought to assess the role of traffic-related air pollution (TRAP) on respiratory outcomes in BPD.</p>

<p><strong>METHODS: </strong>A total of 784 subjects were included from the Johns Hopkins BPD clinic. Caregivers completed questionnaires on environmental exposures and respiratory outcomes (acute care use and chronic symptoms). Distance to the nearest major roadway was derived from subjects' geocoded residential addresses.</p>

<p><strong>RESULTS: </strong>Approximately half of the subjects (53.8%) lived within 500 m of a major roadway. Subjects who lived within 500 m of a major roadway were more likely to be non-white (P = .006), have a lower estimated household income (P &lt; .001) and live in more densely populated zip codes (P &lt; .001) than those who lived further than 500 m away. For every 1 km increase in distance between residence and roadway, the likelihood of activity limitations decreased by 35% (P = .005). No differences in acute care use were seen with proximity to major roadways.</p>

<p><strong>CONCLUSIONS: </strong>Proximity to a major roadway was associated with chronic respiratory symptoms, such as activity limitations (eg, dyspnea), and tended to be associated with nighttime symptoms as well. Self-reported minorities and families with lower estimated household incomes may be more likely to be exposed to TRAP. Further research is necessary to define the effects of TRAP versus other sources of indoor and outdoor air pollution as well as to determine the best ways of combatting pollution-related respiratory morbidities.</p>

<p><strong>OBJECTIVE: </strong>To evaluate the impact of exposure to indoor air pollution on respiratory health outcomes (healthcare utilization, symptoms, medication use) in infants and children with bronchopulmonary dysplasia (BPD).</p>

<p><strong>STUDY DESIGN: </strong>A total of 244 subjects were included from the Johns Hopkins Bronchopulmonary Dysplasia registry. Parents completed an environmental exposure questionnaire including secondhand smoke and indoor combustion (gas/propane heat, gas or wood stove, gas/wood burning fireplace) exposures in the home. Respiratory symptoms, both acute (healthcare utilization, steroid/antibiotic use) and chronic (cough/wheeze, nocturnal cough, use of beta-agonists, tolerance of physical activity), were also collected.</p>

<p><strong>RESULTS: </strong>Three-quarters of the infants were exposed to at least 1 combustible source of air pollution in the home, and this exposure was associated with an increased risk of hospitalization in infants and children on home respiratory support. Only 14% of the study population reported secondhand smoke exposure, but we found that this was associated with chronic respiratory symptoms, including activity limitation and nocturnal cough. Infants on respiratory support also had increased daytime cough and wheezing. Approximately one-third reported having an air purifier in the home, and its presence attenuated the effect of secondhand smoke exposure on reported activity limitation.</p>

<p><strong>CONCLUSIONS: </strong>Exposure to combustible sources of indoor air pollution was associated with increased respiratory morbidity in a group of high risk of infants with BPD. Our results support that indoor air pollution is a modifiable risk factor for respiratory health in infants with BPD.</p>

<p><strong>CONTEXT: </strong>Treatment options for allergic asthma include allergen avoidance, pharmacotherapy, and allergen immunotherapy.</p>

<p><strong>OBJECTIVES: </strong>Summarize and update current evidence for the efficacy and safety of subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) in pediatric allergic asthma.</p>

<p><strong>DATA SOURCES: </strong>PubMed, Embase, Cochrane Central Register of Controlled Trials (January 1, 2005, through May 8, 2017), ClinicalTrials.gov, and the US Food and Drug Administration Adverse Event Reporting System. We reevaluated trials from our 2013 systematic review.</p>

<p><strong>STUDY SELECTION: </strong>We included studies with children ≤18 years of age in which researchers reported on prespecified outcomes and had an intervention arm receiving aeroallergen SCIT or SLIT. Only randomized controlled trials (RCTs) were included for efficacy. RCTs and non-RCTs were included for safety outcomes.</p>

<p><strong>DATA EXTRACTION: </strong>Two reviewers extracted data. We included 40 studies (17 SCIT trials, 11 SLIT trials, 8 non-RCTs for SCIT safety, and 4 non-RCTs for SLIT safety).</p>

<p><strong>RESULTS: </strong>We found moderate-strength evidence that SCIT reduces long-term asthma medication use. We found low-strength evidence that SCIT improves asthma-related quality of life and forced expiratory volume in 1 second. There was also low-strength evidence that SLIT improves medication use and forced expiratory volume in 1 second. There was insufficient evidence on asthma symptoms and health care use.</p>

<p><strong>LIMITATIONS: </strong>There were no trials in which researchers evaluated asthma symptoms using a validated tool. Study characteristics and outcomes were reported heterogeneously.</p>

<p><strong>CONCLUSIONS: </strong>In children with allergic asthma, SCIT may reduce long-term asthma medication use. Local and systemic allergic reactions are common, but anaphylaxis is reported rarely.</p>