History Of Bronchiolitis Research Articles

Air pollution after acute bronchiolitis is a risk factor for preschool asthma: a nested case-control study

BackgroundAcute bronchiolitis and air pollution are both risk factor of pediatric asthma. This study aimed to assess subsequent exposure to air pollutants related to the inception of preschool asthma in infants with acute bronchiolitis. This study aimed to assess subsequent exposure to air pollutants related to the inception of preschool asthma in infants with acute bronchiolitis.MethodsA nested case-control retrospective study was performed at the Kaohsiung Medical University Hospital systems between 2009 and 2019. The average concentration of PM10, PM2.5, SO2, NO, NO2, and NOX was collected for three, six, and twelve months after the first infected episode. Adjusted regression models were employed to evaluate the association between asthma and air pollution exposure after bronchiolitis.ResultsTwo thousand six hundred thirty-seven children with acute bronchiolitis were included. Exposure to PM10, PM2.5, SO2, NO, NO2, and NOX in the three, six, and twelve months following an episode of bronchiolitis was found to significantly increase the risk of preschool asthma in infants with a history of bronchiolitis.(OR, 95%CI: PM10 = 1.517-1.559, 1.354–1.744; PM2.5 = 2.510-2.603, 2.148–3.061; SO2 = 1.970-2.040, 1.724–2.342; ; NO = 1.915-1.950, 1.647–2.272; NO2 = 1.915-1.950, 1.647–2.272; NOX = 1.752-1.970, 1.508–2.252) In a sensitive analysis of hospitalized infants, only PM10, PM2.5, SO2, and NO were found to have significant effects during all time periods. (OR, 95%CI: PM10 = 1.613-1.650, 1.240–2.140; PM2.5 = 2.208-2.286, 1.568–3.061; SO2 = 1.679-1.622, 1.197–2.292; NO = 1.525-1.557, 1.094–2.181)ConclusionThe presence of ambient PM10, PM2.5, SO2 and NO in the three, six, and twelve months following an episode of acute bronchiolitis has been linked to the development of preschool asthma in infants with a history of acute bronchiolitis.

Long-term ozone exposure and lung function in middle childhood

BackgroundOzone (O3) exposure interrupts normal lung development in animal models. Epidemiologic evidence further suggests impairment with higher long-term O3 exposure across early and middle childhood, although study findings to date are mixed and few have investigated vulnerable subgroups. MethodsParticipants from the CANDLE study, a pregnancy cohort in Shelby County, TN, in the ECHO-PATHWAYS Consortium, were included if children were born at gestational age >32 weeks, completed a spirometry exam at age 8–9, and had a valid residential history from birth to age 8. We estimated lifetime average ambient O3 exposure based on each child's residential history from birth to age 8, using a validated fine-resolution spatiotemporal model. Spirometry was performed at the age 8–9 year study visit to assess Forced Expiratory Volume in the first second (FEV1) and Forced Vital Capacity (FVC) as primary outcomes; z-scores were calculated using sex-and-age-specific reference equations. Linear regression with robust variance estimators was used to examine associations between O3 exposure and continuous lung function z-scores, adjusted for child, sociodemographic, and home environmental factors. Potential susceptible subgroups were explored using a product term in the regression model to assess effect modification by child sex, history of bronchiolitis in infancy, and allergic sensitization. ResultsIn our sample (n = 648), O3 exposure averaged from birth to age 8 was modest (mean 26.6 [SD 1.1] ppb). No adverse associations between long-term postnatal O3 exposure were observed with either FEV1 (β = 0.12, 95% CI: −0.04, 0.29) or FVC (β = 0.03, 95% CI: −0.13, 0.19). No effect modification by child sex, history of bronchiolitis in infancy, or allergic sensitization was detected for associations with 8-year average O3. ConclusionsIn this sample with low O3 concentrations, we did not observe adverse associations between O3 exposures averaged from birth to age 8 and lung function in middle childhood.

Role of Air Pollution in the Development of Asthma Among Children with a History of Bronchiolitis in Infancy.

Infants experiencing bronchiolitis are at increased risk for asthma, but few studies have identified modifiable risk factors. We assessed whether early life air pollution influenced child asthma and wheeze at age 4-6 years among children with a history of bronchiolitis in the first postnatal year. Children with caregiver-reported physician-diagnosed bronchiolitis were drawn from ECHO-PATHWAYS, a pooled longitudinal cohort from six US cities. We estimated their air pollution exposure from age 1 to 3 years from validated spatiotemporal models of fine particulate matter (PM 2.5 ), nitrogen dioxide (NO 2 ), and ozone (O 3 ). Caregivers reported children's current wheeze and asthma at age 4-6 years. We used modified Poisson regression to estimate relative risks (RR) and 95% confidence intervals (CI), adjusting for child, maternal, and home environmental factors. We assessed effect modification by child sex and maternal history of asthma with interaction models. A total of 224 children had caregiver-reported bronchiolitis. Median (interquartile range) 2-year pollutant concentrations were 9.3 (7.8-9.9) µg/m 3 PM 2.5 , 8.5 (6.4-9.9) ppb NO 2 , and 26.6 (25.6-27.7) ppb O 3 . RRs (CI) for current wheeze per 2-ppb higher O 3 were 1.3 (1.0-1.7) and 1.4 (1.1-1.8) for asthma. NO 2 was inversely associated with wheeze and asthma whereas associations with PM 2.5 were null. We observed interactions between NO 2 and PM 2.5 and maternal history of asthma, with lower risks observed among children with a maternal history of asthma. Our results are consistent with the hypothesis that exposure to modest postnatal O 3 concentrations increases the risk of asthma and wheeze among the vulnerable subpopulation of infants experiencing bronchiolitis.

Type 2 cytokine genes as allergic asthma risk factors after viral bronchiolitis in early childhood.

Genome-wide association studies of asthma have identified associations with variants in type-2 related genes. Also, specific interactions between genetic variants and viral bronchiolitis in the development of asthma has been suggested. To conduct a gene-based analysis of genetic variants in type 2 cytokine related genes as risk factors for allergic asthma at school age, and further, to study their interaction with specific viral infections in early childhood. A prospectively investigated cohort of children with previous bronchiolitis and controls came for follow-up at school age. The research visit, blinded to viral exposure, included detailed lung function tests, laboratory investigation, and questionnaires. Allergic asthma was defined as typical symptoms plus objective variable airway obstruction, in addition to laboratory verified atopy (elevated eosinophil count or sensitization to an allergen). Targeted and complete sequencing was performed for nine type 2 cytokine candidate genes: IL4, 5, 13, 25, 33 and 37, IL17RB, CRLF2 and TSLP. At follow-up, there were 109 children with genetic data, 91 with a history of bronchiolitis (46% respiratory syncytial virus, 24% human rhinovirus, 15% human metapneumovirus and 14% mixed viral etiology) and 18 without. The median age was 9.4 years (range 6-13) and 41 (38%) had laboratory verified atopy. Twenty-one children (19%) met the definition of allergic asthma. After adjusting for age, sex and five viral categories, IL33 achieved nominal significance (p = 0.017) for a positive association with allergic asthma development. In the gene-virus interaction analysis, the variant set in IL17RB demonstrated a nominally significant positive interaction with human metapneumovirus infection (p=0.05). The results highlight the multifactorial nature of allergic asthma risk, with both viral infection and inherited genetic variants contributing to increasing risk. Results for IL33 and IL17RB were nominally significant and are potential candidate targets for designing therapeutics and early screening, but these results must be replicated in an independent study.

Infant Exposure to Acid Suppressant Medications Increases Risk of Recurrent Wheeze and Asthma in Childhood

Acid suppressant medications (ASMs) are commonly prescribed in infancy. Little is known about the relationship between ASM exposure and risk of childhood asthma and atopic conditions. We sought to examine the association between infant ASM exposure and risk for developing recurrent wheeze, allergen sensitization, and asthma in early childhood. We used data from a diverse, multicenter, prospective cohort study of 921 infants with a history of bronchiolitis. ASM exposure (histamine-2 receptor antagonists and/or proton pump inhibitors) during infancy (age: <12 months) was ascertained by parent report and medical record review. The outcomes were recurrent wheeze by age 3 years, early childhood allergen sensitization (serum specific IgE), and asthma by age 6 years. We constructed multivariable Cox proportional hazards models and multivariable logistic regression models adjusting for multiple confounders. Of the 921 children in the cohort, 202 (22%) were exposed to ASMs during infancy. Compared with unexposed children, those exposed to ASM were more likely to develop recurrent wheeze by age 3 years (adjusted hazard ratio: 1.58, 95% confidence interval [CI]: 1.20-2.08, P= .001) and asthma by age 6 years (adjusted odds ratio: 1.66, 95% CI: 1.22-2.27, P= .001). ASM exposure during infancy was not significantly associated with the development of early childhood allergen sensitization (adjusted odds ratio: 1.00, 95% CI: 0.70-1.44, P=.99). Although exposure to ASMs during infancy does not increase the risk of allergen sensitization in early childhood, ASM exposure during infancy increases the risk of recurrent wheeze and asthma during early childhood.

Risk Factors Associated With Health Care Utilization in Preschool Recurrent Wheezers in a Tropical Environment.

Introduction: The severity of wheezing episodes is related with the need for health services, but the factors associated with health care utilization in preschool recurrent wheezers in underdeveloped regions are unclear.Objective: To evaluate the factors associated with health care utilization in preschool recurrent wheezers in Cartagena, Colombia.Methods: One hundred twenty-seven recurrent wheezers (age 2–6 years old) who were admitted to the emergency room (ER) due to wheezing in a Pediatric reference hospital in Cartagena were included. Children were evaluated by means of questionnaires and classified according to the number of ER visits, need for hospitalization and history of intensive care unit (ICU) admission due to wheezing within the last year. Total serum IgE and specific IgE to house dust mite allergens (HDM) were measured by ImmunoCAP® and allergen sensitization was evaluated by skin prick tests (SPT).Results: The maternal report of nocturnal cough without fever in their children increased the risk to have ≥5 ER visits in the last year due to wheezing. The use of montelukast was negatively associated with hospitalization, while a history of pneumonia and lack of tap water, increased the risk of hospitalization due to wheezing. A history of bronchiolitis, family history of asthma, cohabiting with two or more siblings, passive exposure to smoke and lack of sewage facilities increased the risk of ICU admission due to wheezing. The presence of atopy evaluated by SPT reactivity, total IgE levels or specific IgE to HDM were not associated with health care utilization. We also found that seroprevalence of positive IgE (≥0.35 kU/L) was 27% to B. tropicalis and 20.3% to D. pteronyssinus but the prevalence of positive IgE sensitization to these allergens was below 2% and 8% when evaluated by SPT, respectively.Conclusions: Poverty indicators are associated with ICU admission in a group of preschool recurrent wheezers and should be considered as aggravating factors for wheezing. These factors must be systematically assessed in the medical approach in underdeveloped regions in the tropics. Nocturnal cough without fever is a symptom associated with frequent ER visits while atopy was not associated with health care utilization in preschool recurrent wheezers.

Allergic rhinitis is associated with atmospheric SO2: Follow-up study of children from elementary schools in Ulsan, Korea.

ObjectivesThe purpose of this study was to examine the association of allergic rhinitis with air pollutant concentrations using the follow-up data of elementary school children in Ulsan, Korea.MethodsAll students of four elementary schools in Ulsan, South Korea were surveyed at two-year intervals. The survey used data collected five times, over a nine-year period from June 2009 to April 2018. The questionnaire used in the survey was a modified version of the ISAAC (International society of asthma and allergy of children) questionnaire. A skin prick test (SPT) was performed with 24 standard antigens. To estimate the levels of exposure to outdoor air pollution, the concentrations of sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), carbon monoxide (CO), and particulate matter 10 μm or less in diameter (PM10) were used. As a dependent variable, a history of allergic rhinitis diagnosed by a doctor during the last 1-year was considered. Logistic regression analysis was used to select variables suitable for the statistical model. The selected variables were then used to assess their association with the dependent variable using the generalized estimation equation.ResultsAmong environmental factors, SO2 was associated with a high risk and PM10 was associated with a low risk of allergic rhinitis. The risk of allergic rhinitis from living in a house built within the last year was high, and the risk from living in a multi-family house or apartment was higher than that from living in a segregated house. History of allergic diseases in the family was a high-risk factor for allergic rhinitis. There was a relationship between a history of bronchiolitis at less than 2 years of age and a high risk of allergic rhinitis. Boys were at a higher risk than girls.ConclusionFrom the follow-up data of elementary school students in Ulsan, Korea, the concentration of SO2, which is an indicator of the degree of industrialization, was related to the prevalence of allergic rhinitis. Among all the risk factors, history of allergic disease in the parents was the most important factor, and the study reconfirmed the results of the previous studies.

Risk factors for the development of asthma symptoms in children with allergic rhinitis

Purpose: Both allergic rhinitis and asthma are considered one airway disease, which interacts with each other in disease onset and symptom worsening. We evaluated factors developing new or persistent asthma symptoms in elementary school children with al lergic rhinitis. Methods: We selected 343 children aged 6 to 7 years who had rhinitis symptoms within 12 months and allergic sensitization on skin prick tests among 2,491 elementary school children. The questionnaires on symptoms, medical history and environments, blood eosinophils, serum total IgE, pulmonary function test, and bronchial provocation tests were obtained. Using multiple regression analysis, we evaluated factors for later asthma symptoms during a follow-up period of 4 years. Results: The independent risk factors for later asthma symptoms among children with allergic rhinitis were higher body mass index (adjusted odds ratio [aOR], 1.29; 95% confidence interval [CI], 1.06-1.56; P=0.012), a parental diagnosis of asthma (aOR, 6.19; 95% CI, 1.59-24.06; P=0.008), residence in the rural area (aOR, 5.37; 95% CI, 1.34-21.42; P=0.017), and a history of bronchiolitis in the first 2 years (aOR, 5.82; 95% CI, 1.42-23.80; P=0.014). However, pulmonary functions, the levels of bronchial hyper-responsiveness, and the patterns of sensitization showed not significant factors. Children whose allergic rhinitis was treated in the follow-up period were less likely to have asthma symptoms later (aOR, 0.30; 95% CI, 0.10-0.93; P=0.036). Conclusion: In the school-aged children with allergic rhinitis, body mass index and asthma-related risk factors are crucial for devel oping asthma symptoms. The appropriate treatment of rhinitis may decrease asthma symptoms. (Allergy Asthma Respir Dis 2020;8:191-198)

Factores relacionados con el desarrollo del asma en la infancia, en un grupo de niños de 6 a 14 años en 2 colegios de la ciudad de Cali (Colombia)

IntroductionAsthma is a respiratory disease, characterised by recurrent attacks of dyspnoea and wheezing, which vary in severity and frequency from one person to another. Despite being a common disease in children in our region, not enough studies have been conducted on the subject. The aim of this study was to identify some factors related to the development of asthma in childhood, in a group of children from 6 to 14 years old in 2schools in the city of Cali. MethodA cross-sectional study was performed by collecting information using the questionnaire of the ISAAC phase II studies. This questionnaire was completed by the caregivers of the 6 to 14 year-old schoolchildren. ResultsA total of 1273 questionnaires were sent to caregivers. Of the 324 analysed, 80% of the children were between 6 to 11 years of age, of whom 57% were girls. Just over half (54%) were of medium socioeconomic status, and 50% claimed to be of mixed race. The prevalence of asthma for this population was 23.8%, being higher in ages from 12 to 14 years with 45%, and higher in boys. It was found that the prevalence was associated with the age of the child and previous illnesses, such as asthma and bronchiolitis, as well as environmental factors such as smoking at home and inadequate soil quality. ConclusionsThe prevalence of asthma was 23.8%. The age of the children, history of bronchiolitis, and smoking at home are factors related to childhood asthma.

Characterization of children younger than five years with suspected allergic diseases

Symptoms of allergic diseases are a common cause of consultation during childhood. To describe the profile of a population of Colombian preschool children seen in an allergology department and assess possible risk factors. Descriptive, cross-sectional study of patients younger than 5 years who were assessed for one year. A complete medical history was obtained and allergology workup was carried out with skin prick tests as appropriate for each case. Risk factors were assessed by means of multivariate analysis. A total of 674 patients were included, out of which 382 (52.7%) were males. Median age was 34 months. The reasons for consultation were cough or recurrent wheezing (54.3%), rhinitis (48.7%), and eczema (32.2%). Skin prick tests were performed with aeroallergens in 299 patients (48%) and with food in 170 (27%), with positivity being found in 114 (38%) and 16 (9.4%), respectively. Main sensitizers were dust mites and egg. A direct association was found between eczema and prematurity (OR = 0.496; 95 % CI = 0.289-0.823)], between recurrent cough/wheezing and family history of allergy (OR = 1.837; 95 % CI = 1,306-2,586), and between recurrent cough/wheezing and history of bronchiolitis (OR = 2.646; 95 % CI = 1.812-3.886). Respiratory symptoms represented the main cause of consultation. Dust mites were the most commonly identified allergens. Family history of allergy and bronchiolitis.

Prevalence, Risk Factors and Cutoff Values for Bronchial Hyperresponsiveness to Provocholine in 7-Year-Old Children

BackgroundA US Food and Drug Administration (FDA)-approved drug methacholine chloride (Provocholine®) was recently introduced to Korea where it is now widely used in clinical practice. We aimed to evaluate the prevalence, risk factors and cutoff value of bronchial hyperresponsiveness (BHR) to Provocholine in 7-year-old children.MethodsSix hundred and thirty-three children from the Panel Study on Korean Children who visited 16 regional hospitals were evaluated. Skin prick tests, spirometry and bronchial provocation tests for Provocholine as well as a detailed history and physical examinations were performed. The bronchial provocation test was reliably performed on 559 of these children.ResultsThe prevalence of ever-diagnosed asthma via medical records was 7.7%, and that of current asthma (wheezy episode in the last 12 months + diagnosed asthma by physicians) was 3.2%. The prevalence of BHR to Provocholine was 17.2% and 25.8%, respectively, for a PC20 < 8 and < 16 mg/mL. The risk factors for BHR (PC20 < 16 mg/mL) were atopic dermatitis diagnosis and current dog ownership, whereas those for current asthma were allergy rhinitis diagnosis, a history of bronchiolitis before the age of 3, recent use of analgesics/antipyretics and maternal history of asthma. The BHR prevalence trend showed an increase along with the increased immunoglobulin E (IgE) quartile. The cutoff value of PC20 for the diagnosis of current asthma in children at age 7 was 5.8 mg/mL (sensitivity: 47.1%, specificity: 87.4%).ConclusionsBHR to Provocholine (PC20 < 8 mg/mL) was observed in 17.2% of 7-year-olds children from the general population and the cutoff value of PC20 for the diagnosis of current asthma was 5.8 mg/mL in this age group. The risk factors for BHR and current asthma showed discrepancies suggesting different underlying mechanisms. Bronchial provocation testing with Provocholine will be a useful clinical tool in the future.

Association Between Antibiotic Exposure, Bronchiolitis, and TLR4 (rs1927911) Polymorphisms in Childhood Asthma.

PurposeThe complex interplay between environmental and genetic factors plays an important role in the development of asthma. Several studies have yielded conflicting results regarding the 2 asthma-related risk factors: antibiotic usage during infancy and/or a history of bronchiolitis during early life and the development of asthma. In addition to these risk factors, we also explored the effects of Toll-like receptor 4 (TLR4) polymorphism on the development of childhood asthma.MethodsThis cross-sectional study involved 7,389 middle school students who were from 8 areas of Seoul, Korea, and completed the International Study of Asthma and Allergies in Childhood questionnaire. The TLR4 polymorphism rs1927911 was genotyped in 1,395 middle school students from two areas using the TaqMan assay.ResultsBronchiolitis in the first 2 years of life, antibiotic exposure during the first year of life, and parental history of asthma were independent risk factors for the development of asthma. When combined, antibiotic use and a history of bronchiolitis increased the risk of asthma (adjusted odds ratio [aOR]: 4.64, 95% confidence interval [CI]: 3.09-6.97, P value for interaction=0.02). In subjects with CC genotype of TLR4, antibiotic exposure and a history of bronchiolitis during infancy, the risk of asthma was increased, compared to subjects without these risk factors (aOR: 5.72, 95% CI: 1.74-18.87).ConclusionsEarly-life antibiotic exposures and a history of bronchiolitis are risk factors for asthma in young adolescents. Polymorphisms of TLR4 modified the influence of these environmental factors. Reducing antibiotic exposure and preventing bronchiolitis during infancy may prevent the development of asthma, especially in genetically susceptible subjects.

Air Pollution Interacts With Past Episodes of Bronchiolitis in the Development of Asthma

To evaluate whether air pollution affects the development of asthma in children with previous episodes of bronchiolitis.A total of 1743 children, with a mean age of 6.83 years, were included in this study. Children were recruited from 16 elementary schools in 7 cities throughout Korea. A total of 1340 of these children were followed up 2 years later.All children had parental completion of the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire and an allergy evaluation consisting of pulmonary function tests, skin-prick testing, and a methacholine challenge at the time of enrollment. Air pollution was calculated as an average of the concentrations of ozone, carbon monoxide, nitric dioxide, sulfur dioxide, and particulate matter <10 μm in diameter between 2001 and 2005, based on a geographic sampling system.Higher exposure to ozone and carbon monoxide was associated with airway hyperresponsiveness at the time of enrollment. Previous episodes of bronchiolitis increased the child’s risk of both current wheezing and physician-diagnosed asthma. When the 2 factors were combined, the risk of airway hyperresponsiveness, wheezing, physician-diagnosed asthma, and decreased pulmonary function test results was higher.In children, those who had both a history of bronchiolitis and exposure to higher amounts of air pollution were found to have a higher prevalence of asthma, heightened bronchial reactivity, and decreased lung function compared with children without these exposures.This study is novel in that it is the first to reveal an apparently synergistic effect between bronchiolitis and air pollution on the development of asthma in children. Further research is needed into the mechanisms of this synergy, as well as possible targets for intervention, to prevent the development of asthma in this high-risk population.

Modifiable exposures to air pollutants related to asthma phenotypes in the first year of life in children of the EDEN mother-child cohort study

BackgroundStudies have shown diverse strength of evidence for the associations between air pollutants and childhood asthma, but these associations have scarcely been documented in the early life. The purpose of this study was to evaluate the impacts of various air pollutants on the development of asthma phenotypes in the first year of life.MethodsAdjusted odds ratios were estimated to assess the relationships between exposures to air pollutants and single and multi-dimensional asthma phenotypes in the first year of life in children of the EDEN mother-child cohort study (n = 1,765 mother-child pairs). The Generalized Estimating Equation (GEE) model was used to determine the associations between prenatal maternal smoking and in utero exposure to traffic-related air pollution and asthma phenotypes (data were collected when children were at birth, and at 4, 8 and 12 months of age). Adjusted Population Attributable Risk (aPAR) was estimated to measure the impacts of air pollutants on health outcomes.ResultsIn the first year of life, both single and multi-dimensional asthma phenotypes were positively related to heavy parental smoking, traffic-related air pollution and dampness, but negatively associated with contact with cats and domestic wood heating. Adjusted odds ratios (aORs) for traffic-related air pollution were the highest [1.71 (95% Confidence Interval (CI): 1.08-2.72) for ever doctor-diagnosed asthma, 1.44 (95% CI: 1.05-1.99) for bronchiolitis with wheezing, 2.01 (95% CI: 1.23-3.30) for doctor-diagnosed asthma with a history of bronchiolitis]. The aPARs based on these aORs were 13.52%, 9.39%, and 17.78%, respectively. Results persisted for prenatal maternal smoking and in utero exposure to traffic-related air pollution, although statistically significant associations were observed only with the asthma phenotype of ever bronchiolitis.ConclusionsAfter adjusting for potential confounders, traffic-related air pollution in utero life and in the first year of life, had a greater impact on the development of asthma phenotypes compared to other factors.

High asthma prevalence and increased morbidity among rural children in a Medicaid cohort

Urban children represent a group at high risk for asthma development and adverse asthma outcomes. Although rural children also encounter sociodemographic disparities that might be expected to worsen asthma, asthma in the rural United States is poorly studied. To determine rural-urban differences in childhood asthma diagnosis and morbidity. We studied a statewide population of 117,080 children continuously enrolled in Tennessee Medicaid from birth through the sixth year of life, using linked Tennessee Medicaid, vital records, and pharmacy claims databases to determine asthma diagnosis and residence. The cohort was 45% urban, 23% suburban, and 33% rural. Compared with urban children, rural children were more likely to be white, have a history of bronchiolitis, and have mothers who smoked. Eleven percent of urban, 12% of suburban, and 13% of rural children met study criteria for asthma diagnosis (adjusted odds ratio for rural children, 1.16; 95% confidence interval, 1.09-1.24; adjusted odds ratio for suburban children, 1.22; 95% confidence interval, 1.14-1.30; with urban as the referent; P < .001). Rural children had greater use of outpatient asthma care, whereas urban children had greater use of inhaled corticosteroids. Compared with urban children, rural children had fewer asthma emergency department visits but were hospitalized for asthma at similar rates and had similar use of asthma rescue medications. In this pediatric Medicaid population, rural children had increased asthma prevalence and similar asthma morbidity compared with urban children but differences in patterns of asthma care and resource use, suggesting that optimal interventions for asthma may differ in rural compared with urban populations.

Prevalence of Allergic Diseases and Risk Factors in Preschool Children, 2009

Purpose : In Korea, there have been many epidemiologic studies about allergic diseases of school children, but so far only a few studies of preschool children have been done. Research on preschool children will be a great help to understand the epidemiology of the allergic diseases in the pediatric population. In this perspective, we researched the prevalence and risk factors of allergic diseases in preschool children in Jung-gu, Seoul. Methods : A modified International Study of Asthma and Allergies in Childhood questionnaire survey was done on 917 (male, 492; female, 425) preschool children in Jung-gu area of Seoul in June, 2009. Parents or caregivers answered the questionnaires that asked about the prevalence of allergic diseases and the risk factors. Results : For asthma, the prevalence of “wheeze, ever”, “diagnosis” and “treatment, last 12 months” were 18.4%, 5.8% and 2.8%, respectively. For allergic rhinitis (AR), the prevalence of “rhinitis, ever”, “diagnosis” and “treatment, last 12 months” were 31.8%, 16.2% and 12.9%, respectively. For atopic dermatitis (AD), the prevalence of “itchy rash, ever”, “diagnosis” and “treatment, last 12 months” were 26.1%, 34.3% and 19.0%, respectively. The risk factors of asthma were cesarean section delivery, use of antibiotics and history of bronchiolitis before the age of 2 years. The risk factor of AR was history of asthma. The risk factor of AD was parent allergy. Conclusion : In comparison to preceding studies of preschool children in Seoul, the prevalence of allergic diseases is similar. In comparison to the studies of school children, the prevalence of AR was lower and the prevalence of AD was higher. [Pediatr Allergy Respir Dis(Korea) 2011;21: 165-175]

Changes in the Prevalence of Childhood Asthma in Seoul from 1995 to 2008 and Its Risk Factors

PurposeTo investigate the prevalence of asthma and determine its risk factors in elementary school students in Seoul.MethodsA modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was used to survey 4,731 elementary school students from five areas in Seoul between April and October, 2008.ResultsIn elementary school children, the lifetime and recent 12-month prevalence of wheezing were 11.7% and 5.6%, respectively. The lifetime prevalence of asthma diagnosis was 7.9%, and the recent 12-month prevalence of asthma treatment was 2.7%. Male sex (adjusted odds ratio [aOR], 1.90; 95% confidence interval [CI], 1.36-2.66), history of atopic dermatitis (AD) (aOR, 2.76; 95% CI, 1.98-3.84), history of allergic rhinitis (AR) (aOR, 3.71; 95% CI, 2.61-5.26), history of bronchiolitis before 2 years of age (aOR, 2.06; 95% CI, 1.39-3.07), use of antibiotics during infancy for >3 days (aOR, 1.88; 95% CI, 1.35-2.62), parental history of asthma (aOR, 2.83; 95% CI, 1.52-5.27), exposure to household molds during infancy (aOR, 1.84; 95% CI, 1.18-2.89), and the development or aggravation of asthma symptoms within 6 months after moving to a new house (aOR, 11.76; 95% CI, 5.35-25.86) were the independent risk factors for wheezing within 12 months.ConclusionsThe prevalence of wheezing and asthma in elementary school students in 2008 was similar to that in the past decade. Male sex, history of AD, history of AR, history of bronchiolitis before 2 years of age, parental asthma, use of antibiotics during infancy, exposure to molds in the house during infancy, and development or aggravation of asthma symptoms within 6 months after moving to a new house, could be risk factors for wheezing within 12 months.

Pharmacokinetics and Safety of Montelukast Oral Granules in Children 1 to 3 Months of Age With Bronchiolitis

The single-dose pharmacokinetics of montelukast 4-mg oral granules and tolerability of daily administration of 2 different doses of montelukast (4 mg and 8 mg given once daily for 7 days) versus placebo were evaluated in 12 infants 1 to 3 months of age with bronchiolitis or a history of bronchiolitis and asthma-like symptoms. The population area under the concentration-time curve estimate after a single 4-mg dose of montelukast was 13 195.7 +/- 2309.8 (standard error) ng.hr/mL, 3.6 times higher than historical values in infants 3 to 24 months of age. Six patients had 10 total clinical adverse experiences; none was considered serious or drug related. Three patients had transient drug-related increases in aspartate aminotransferase (montelukast 8 mg [n = 2]; placebo [n = 1]). Despite increased systemic exposure after administration of a single dose of montelukast 4-mg oral granules in infants 1 to 3 months of age compared with that in pediatric patients 3 to 24 months of age, administration of montelukast at 4 and 8 mg once daily for 7 days in 1- to 3-month-old infants was generally well tolerated.

Asthma, lung function and sensitization in school children with a history of bronchiolitis

The purpose of the present retrospective study was to investigate the association of school-age asthma with acute-bronchiolitis and examine the influence of potential risk factors. One hundred and eighty-nine children aged 7.5 +/- 2.2 years consecutively hospitalized for respiratory syncytial virus (RSV)-positive acute bronchiolitis during infancy were evaluated by clinical examination and measurement of peak expiratory flow (PEFR), spirometry, IgE and skin-prick testing. Their pulmonary function was compared with that of 60 non-asthmatic matched controls. Of the entire cohort 57.1% were diagnosed as asthmatic. PEFR, the 1-second forced expiratory volume and forced expiratory flow of 50% vital capacity of children with a history of acute bronchiolitis were statistically significantly lower than in the control group (all P < 0.001). All the aforementioned measurements of children with/without asthma were also significantly lower than controls, while values of asthmatics were significantly lower than those of non-asthmatics. The incidence of asthma in childhood was independently associated with breast-feeding <3 months (adjusted odds ratio [aOR], 8.4; 95% confidence interval [CI]: 3.1-22.4), at least one positive skin prick test (aOR, 7.1; 95%CI: 2.8-18.1), male gender (aOR, 5.0; 95%CI: 2.2-11.5), evidence of moisture in the home environment (aOR, 2.9; 95%CI: 1.3-6.3) and presence of more than one house-resident smoking indoors (aOR, 4.9; 95%CI: 1.8-9.2). Children with a history of RSV-bronchiolitis during infancy have an increased risk for developing asthma in childhood, which was independently associated with male gender, breast-feeding <3 months, living in a home environment with moisture damage and/or tobacco smoke by two or more residents and sensitization to at least one aeroallergen. Children with a history of RSV bronchiolitis in infancy had lower spirometry in comparison to matched control group. The difference was more marked for asthmatic ones but remained significant even for non-asthmatic children.

The association between birth season and future development of childhood asthma

The aim of this study was to examine a possible association between birth season (date of birth) and future development of asthma in children. A case-control study was designed to include asthmatic children aged 2-7 years, living in the city of Beer-Sheva, in southern Israel, registered in one pediatric center. Controls were healthy children matched for age and registered at the same clinic. Demographic data, past medical history, and asthma history and severity were collected using the computerized medical charts and asthma registry. A structured telephone questionnaire was used to complete the data. Children with a history of prematurity or chronic significant illness were excluded from the study. Sixty-six children and 69 controls were enrolled in the study. There were significantly more males in the asthmatic group compared to controls (P = 0.003). History of bronchiolitis or recurrent wheezing episodes in the first year, family history of asthma, and Middle-Eastern origin were significantly more common among asthmatic children than controls (P < 0.001). Asthmatic children were more likely to be born between March and June and least likely to be born between October and December, compared to controls (P < 0.05). Multivariate logistic regression analysis revealed three variables to be independent significant risk factors for development of asthma: birth season between March and June, acute bronchiolitis or recurrent wheezing episodes during first year of life, and male gender. Birth season during late winter and spring is associated with asthma during childhood.