International Study of Asthma and Allergies in Childhood (ISAAC): rationale and methods

Parental occupational exposures prior to conception and offspring wheeze and eczema during first year of life

PURPOSE

Parental exposures prior to conception might influence asthma and allergy risk in offspring. As occupational exposures are established risk factors for asthma and allergies, we investigated if parental occupational exposures prior to conception cause wheeze and eczema in offspring during the first year of life.

METHODS

We analysed data of 436 families from an offspring cohort based on a follow-up study of German participants of the International Study of Asthma and Allergies in Childhood (ISAAC). Offspring cohort data was collected between 2009 and 2019. Occupational exposures were based on participants' work histories and measured by a Job-Exposure-Matrix. We used Bayesian logistic regression models for analysis. Inference and confounder selection were based on directed acyclic graphs.

RESULTS

In mothers, for both allergic and irritative occupational exposures prior to conception suggestive effects on offspring eczema during the first year of life were found (allergens: odds ratio (OR) 1.22, 95% compatibility interval (CI) 0.92-1.57; irritants: OR 1.36, 95% CI 0.99-1.77), while no relation with wheeze was suggested.

CONCLUSIONS

Our results suggest that reduction of asthma-related occupational exposures might not only reduce the burden of disease for occupationally induced or aggravated asthma and allergies in employees but also in their children.

Long-Term Results of Pediatric Congenital Pulmonary Malformation: A Population-Based Matched Case-Control Study with a Mean 7-Year Follow-Up

Symptomatic congenital pulmonary malformations (CPMs) are a group of anomalies involving the lungs. The long-term outcomes of these patients are not well known. The present research aimed to study the pulmonary function, respiratory morbidity, and health-related quality of life (QoL) of patients treated for CPMs. All children (<16 years of age) treated for CPMs in 2002−2012 (in Oulu University Hospital) were invited to the follow-up visit. Altogether, there were 22 patients, out of which 17 (77%) participated. The mean follow-up time was 6.6 (ranged from 3 to 16) years. Pulmonary function tests, diffusing capacity, respiratory morbidity, and QoL were determined as the primary outcomes. Potential residual malformations and lung anatomy were investigated using computer tomography (CT) imaging. The outcomes were compared to the age- and sex-matched healthy controls. The forced expiratory volume at 1 s (FEV1, Z-score) remained lower in operated patients compared to the healthy controls (−1.57 ± SD 1.35 vs. −0.39 ± SD −0.86, p-value 0.005). There were no differences in respiratory morbidity or QoL between the patients and the controls. The surgical approach (lobectomy vs. partial resection) did not affect lung function. A younger age (<1 year of age) at the time of the surgery seemed to result in a higher lung capacity, but the finding was not statistically significant. Patients with CPMs treated with surgery were satisfied with their wellbeing in the long-term. A lower lung function did not have an impact on their wellbeing. However, there was a slight decrease in lung function compared to the healthy controls, and a clinical follow-up of the patients was recommended.

Maternal Diet Quality during Pregnancy and Allergic and Respiratory Multimorbidity Clusters in Children from the EDEN Mother-Child Cohort

We investigated the associations between maternal diet quality and allergic and respiratory diseases in children. Analyses were based on 1316 mother-child pairs from the EDEN mother-child cohort. Maternal diet quality during pregnancy was assessed through a food-based score (the Diet Quality), a nutrient-based score (the PANDiet), and the adherence to guidelines for main food groups. Clusters of allergic and respiratory multimorbidity clusters up to 8 years were identified using Latent Class Analysis. Associations were assessed by adjusted multinomial logistic regressions. Four clusters were identified for children: "asymptomatic" (67%, reference group), "asthma only" (14%), "allergies without asthma" (12%), "multi-allergic" (7%). These clusters were not associated with mother diet quality assessed by both scores. Children from mothers consuming legumes once a month or less were at higher risk of belonging to the "multi-allergic" cluster (odds ratio (OR) (95% confidence interval (95%CI)) = 1.60 (1.01;2.54)). No association was found with other food groups or other clusters. In our study, allergic and respiratory multimorbidity in children was described with four distinct clusters. Our results suggest an interest in legumes consumption in the prevention of allergic diseases but need to be confirmed in larger cohorts and randomized control trials.

Endotoxin concentration and persistent eczema in early childhood

Although endotoxin concentration in the environment is negatively associated with atopic dermatitis (AD) onset in early childhood, the association between endotoxin concentration in the environment and eczema resolution in children with preexisting eczema is unclear. The aim of this study was to evaluate the association between endotoxin concentration in house dust and eczema persistence in young children. The authors used data from children participating in JECS (Japan Environment and Children's Study). In children who had AD or AD-like lesions at the age of 1 year, the authors investigated the association between the prevalence of eczema at the age of 3 years and endotoxin concentration (categorized by quartiles) in the dust on children's mattresses at the ages of 1.5 and 3 years. This study included 605 children. Eczema was significantly less prevalent among children whose mattresses were in the second and third quartiles of endotoxin concentration when they were 18 months old than among children whose mattresses were in the first quartile (adjusted odds ratio, 0.57 [95% confidence interval, 0.35-0.93] and adjusted odds ratio, 0.49 [95% confidence interval, 0.29-0.83], respectively). Moreover, of the children with eczema at age 3 years, those whose mattresses had endotoxin concentrations in the first quartile had significantly worse sleep disturbance caused by itchy rash (>1 time per week) than did those whose mattresses were in the third and fourth quartiles (20.0% vs 3.3% and 3.7%, both p values < 0.01). The findings indicate that low endotoxin exposure is associated with a higher prevalence of persistent eczema during early childhood.

Multiple overlapping risk factors for childhood wheeze among children in Benin

BACKGROUND

The African continent is currently facing an epidemiological transition characterized by a shift from communicable to non-communicable diseases. Prominent amongst the latter are allergies and asthma. In that context, wheeze has multiple potential contributory factors that could include some of the endemic helminth infections, as well as environmental exposures, such as household air pollution. We sought to determine the relative importance of these risk factors among children in Benin.

METHODS

We included 964 children aged 6-14 years living in the commune of Comé, south-west Benin. All children were participants in the longitudinal monitoring cohort of the DeWorm3 trial designed to evaluate multiple rounds of community mass treatment with albendazole for interruption of the transmission of soil transmitted helminths (STH). We administered a standard ISAAC questionnaire to determine the presence of wheeze. In addition, we assessed exposure to household air pollution and to other potential allergy-inducing factors, dietary intake and anthropometry. Using STH infection status assessed at the pretreatment baseline timepoint, we used multivariate statistical modelling, controlling for covariates, to investigate associations between wheeze and the different factors measured.

RESULTS

The prevalence of wheezing history was 5.2%, of current wheezing was 4.6% and of severe wheezing was 3.1%, while STH infections were found in 5.6% of children. These profiles did not vary as a function of either age or gender. Infection with Ascaris lumbricoides, but not hookworm species, was significantly associated with both current wheeze (adjusted Odds Ratio (aOR) = 4.3; 95% CI [1.5-12.0]) and severe wheeze (aOR = 9.2; 95% CI [3.1-27.8]). Significant positive associations with current wheeze, independent of each other and of STH infection status, were also found for (i) use of open cookstoves (aOR = 3.9; 95% CI [1.3-11.5]), (ii) use of palm cakes for fire lighting (aOR = 3.4; 95% CI [1.1-9.9]), (iii) contact with domestic animals and/or rodents (aOR = 2.5; 95% CI [1.1-6.0]), (iv) being overweight (aOR = 9.7; 95% CI [1.7-55.9]). Use of open cookstoves and being overweight were also independent risk factors for severe wheeze (aOR = 3.9; 95% CI [1.1-13.7]) and aOR = 10.3; 95% CI [1.8-60.0], respectively).

CONCLUSIONS

Children infected with A. lumbricoides appear to be at elevated risk of wheeze. Deworming may be an important intervention to reduce these symptoms. Improving cooking methods to reduce household air pollution, modifying dietary habits to avoid overweight, and keeping animals out of the house are all additional measures that could also contribute to reducing childrens' risk of wheeze. Policymakers in LMIC should consider tailoring public health measures to reflect the importance of these different risk factors.

Eczema among adolescents in Kuwait: Prevalence, severity, sleep disturbance, antihistamine use, and risk factors

Background

Eczema (atopic dermatitis) is a common inflammatory skin disease that is more prevalent in children and adolescents than adults. In Kuwait, there is a lack of empirical knowledge on eczema epidemiology among adolescents. Therefore, this study aimed to estimate the prevalence of eczema symptoms and severity, assess the frequency of eczema-related nocturnal sleep disturbance and its relation to antihistamine use, and determine factors that are associated with eczema prevalence and eczema-related nocturnal sleep disturbance.

Methods

A school-based cross-sectional study enrolled adolescents (n = 3864) aged 11-14 years across Kuwait. Information on eczema symptoms and clinical history, use of antihistamines, parental history of eczema, mode of delivery, and childhood life-style factors and exposures were reported by parents. Current eczema was defined as chronic or chronically relapsing itchy dermatitis with characteristic morphology and distribution in the past 12 months. Among subjects reporting current itchy rash, frequency of nocturnal sleep disturbance due to itchy rash in the past 12 months was reported as: never, <1 night per week, and ≥1 nights per week. Associations were assessed by applying a modified Poisson regression to estimate adjusted prevalence ratios (aPR) and 95% confidence intervals (CI).

Results

The prevalence estimate of current (past 12 months) itchy rash was 20.5% (735/3593) and current eczema was 10.2% (388/3791), with 19.5% (736/3775) reporting history of ever doctor-diagnosed eczema. Among subjects with current itchy rash, nocturnal sleep disturbance due to itchy rash affected 21.7% (157/724) of participants for <1 night per week and affected 12.7% (92/724) of participants for ≥1 nights per week. Antihistamine use at least once per month increased as the frequency of nocturnal sleep disturbance due to itchy rash increased (P_trend <0.001). Factors that demonstrated association with current eczema prevalence included underweight body mass index (aPR = 1.71, 95% CI: 1.16-2.53), Cesarean section delivery (1.29, 1.01-1.65), and maternal (1.72, 1.35-2.19) and paternal (1.83, 1.44-2.32) history of eczema. Frequent (≥1 nights per week) nocturnal sleep disturbance was associated with Cesarean section delivery (1.98, 1.37-2.85), exposure to household tobacco smoke (1.70, 1.18-2.47), and dog-keeping (1.93, 1.06-3.52).

Conclusions

Eczema symptoms are common among adolescents in Kuwait, with similar epidemiological patterns as those observed in western countries. A large proportion of affected adolescents reported nocturnal sleep disturbance due to itchy rash. Modifiable risk factors were associated increased prevalence of eczema and night awakenings.

Prevalence of asthma and its symptoms in Sri Lankan adults

BACKGROUND

Data on adult asthma is scarce in Sri Lanka. The objective of this study was to estimate the prevalence of asthma and its symptoms in adult Sri Lankans.  METHODS: A cross-sectional study using a translated version of the European Community Respiratory Health Survey screening questionnaire on subjects ≥ 18 years from 7 provinces in Sri Lanka was conducted. The asthma was defined as "wheezing in the past 12 months (current wheeze)", self-reported asthma attack in the past 12 months or on current asthma medication use.

RESULTS

Among 1872 subjects (45.1% males, 48.8% between 18-44 years of age), the prevalence of current wheeze was 23.9% (95%CI: 22.0%-25.9%), self-reported asthma was 11.8% (95%CI: 10.3%-13.2%) and current asthma medication use was 11.1% (95% CI: 9.6%-12.5%). The prevalences were higher in adults > 44 years, 31.4% positively responded to any of the above questions (95%CI: 29.3%-33.4%) and 60.9% of current wheezers did not report having asthma whilst 38.2% used asthma medication. Among current wheezers, 80.1% had at least one other symptom, cough being the commonest. Those with no current wheeze, self-reported asthma and on current asthma medication use, 30%, 35.9% and 36.6%, respectively, reported at least one other symptom. Smokers comprises 22% current wheezers, 20.6% of self-reported asthmatics and 18.7% of current asthma medication users.

CONCLUSIONS

The prevalence of asthma in Sri Lankan adults is higher than the other South Asian countries and higher in the older age group. A significant percentage of symptomatic individuals did not report having asthma or being on medication.

Early-life risk factors for development of asthma from 8 to 28 years of age: a prospective cohort study

Background

The objective was to estimate the incidence rate of asthma from age 8 to 28 years and evaluate early-life risk factors for asthma onset at different ages.

Methods

In 1996, within the Obstructive Lung Disease in Northern Sweden (OLIN) studies, a cohort of 3430 schoolchildren (97% of invited) was recruited at age 8 years to a prospective study about asthma. The cohort was followed annually from age 8 to 19 years and at 28 years by questionnaire surveys (67% of the original cohort participated). Asthma was categorised as never-asthma, onset age ≤8 years, onset age 9-13 years, onset age 14-19 years or onset age >19 years.

Results

Of the 3430 individuals in the cohort, 690 (20.1%) reported asthma in any survey. The average incidence rate was 10.0/1000 per year at ≤8 years, 11.9/1000 per year at 9-13 years, 13.3/1000 per year at 14-19 years and 6.1/1000 per year at >19 years. The incidence was higher among boys until age 10 years, but from age 15 years, it became higher among girls. Family history of asthma, allergic sensitisation and breastfeeding <3 months were associated with asthma onset throughout the study. Low birthweight, maternal smoking during pregnancy, severe respiratory infection, rhinoconjunctivitis and eczema were associated with asthma onset ≤8 and 9-13 years.

Conclusions

The incidence of asthma was high during childhood and the teenage period, and decreased substantially during young adulthood. Early-life factors were associated with asthma onset throughout childhood but had also a lasting effect on asthma incidence until adulthood.

A survey of allergic conjunctivitis in children in China

To explore the risk factors for allergic conjunctivitis (AC) in Chinese children. We recruited 176 children who suffered from AC and a control group comprising 131 normal subjects in southern China. Each participant completed a questionnaire and underwent multiple eye examinations and a skin prick test (SPT). The data of the questionnaire, the scores of the symptoms/signs and the results of the SPT were analysed. The rate of parental allergic history in the case group was much higher than that in the control group (P < 0.01). Compared with the control group, the case group was more likely to have other concomitant diseases (P < 0.01). The scores of ocular symptoms/signs had a significant correlation with the clinical duration of AC in the case group (P < 0.01). Children with other concomitant diseases or a parental allergic history were more likely to have AC.

Prematurity-associated wheeze: current knowledge and opportunities for further investigation

Prematurity-associated wheeze is a common complication of preterm birth, with significant impact on the health and healthcare utilization of former preterm infants. This wheezing phenotype remains poorly understood and difficult to predict. This review will discuss the current state of the literature on prematurity-associated wheeze. We will discuss etiology and pathophysiology, and offer two conceptual models for the pathogenesis of this complex condition. This review will also identify current methods of ascertainment, and discuss the strengths and limitations of each. We will explore research-backed approaches to prevention and management, and finally suggest both pre-clinical and clinical avenues for investigation. An in-depth understanding of prematurity-associated wheeze will aid clinicians in its diagnosis and management, and inspire scientists to pursue much-needed further study into causes and prevention of this common and impactful condition. IMPACT: There is no recent, concise review on the current state of research on prematurity-associated wheeze, which is a rapidly evolving area of study. This article highlights causal models of wheeze, methods of ascertainment, management strategies for the clinician, and opportunities for further research for the physician scientist.

Maternal exposure to urinary polycyclic aromatic hydrocarbons (PAH) in pregnancy and childhood asthma in a pooled multi-cohort study

BACKGROUND

Prenatal exposure to polycyclic aromatic hydrocarbons (PAH) may increase risk of pediatric asthma, but existing human studies are limited.

OBJECTIVES

We estimated associations between gestational PAHs and pediatric asthma in a diverse US sample and evaluated effect modification by child sex, maternal asthma, and prenatal vitamin D status.

METHODS

We pooled two prospective pregnancy cohorts in the ECHO PATHWAYS Consortium, CANDLE and TIDES, for an analytic sample of N = 1296 mother-child dyads. Mono-hydroxylated PAH metabolites (OH-PAHs) were measured in mid-pregnancy urine. Mothers completed the International Study on Allergies and Asthma in Childhood survey at child age 4-6 years. Poisson regression with robust standard errors was used to estimate relative risk of current wheeze, current asthma, ever asthma, and strict asthma associated with each metabolite, adjusted for potential confounders. We used interaction models to assess effect modification. We explored associations between OH-PAH mixtures and outcomes using logistic weighted quantile sum regression augmented by a permutation test to control Type 1 errors.

RESULTS

The sociodemographically diverse sample spanned five cities. Mean (SD) child age at assessment was 4.4 (0.4) years. While there was little evidence that either individual OH-PAHs or mixtures were associated with outcomes, we observed effect modification by child sex for most pairs of OH-PAHs and outcomes, with adverse associations specific to females. For example, a 2-fold increase in 2-hydroxy-phenanthrene was associated with current asthma in females but not males (RRfemale = 1.29 [95 % CI: 1.09, 1.52], RRmale = 0.95 [95 % CI: 0.79, 1.13]; pinteraction = 0.004). There was no consistent evidence of modification by vitamin D status or maternal asthma.

DISCUSSION

This analysis, the largest cohort study of gestational PAH exposure and childhood asthma to date, suggests adverse associations for females only. These preliminary findings are consistent with hypothesized endocrine disruption properties of PAHs, which may lead to sexually dimorphic effects.

Divergent Trends in the Prevalence of Children's Asthma, Rhinitis and Atopic Dermatitis and Environmental Influences in the Urban Setting of Zagreb, Croatia

BACKGROUND

Previous studies have reported that the allergy epidemic in developed countries has reached its plateau, while a rise is expected in developing ones. Our aim was to compare the prevalence of allergic diseases among schoolchildren from the city of Zagreb, Croatia after sixteen years.

METHODS

Symptoms of asthma, allergic rhinitis (AR) and atopic dermatitis (AD) and risk factors were assessed using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. An allergic profile was determined by a skin prick test.

RESULTS

The prevalence of current, ever-in-a-lifetime and diagnosed AR of 35.7%, 42.5% and 14.9% and AD of 18.1%, 37.1% and 31.1% demonstrated a significant increase. The asthma prevalence has remained unchanged. The allergen sensitivity rate has remained similar, but pollens have become dominant. Mould and dog exposure are risks for asthma (OR 14.505, OR 2.033). Exposure to cat allergens is protective in AR (OR 0.277). Parental history of allergies is a risk factor in all conditions.

CONCLUSION

Over sixteen years, the prevalence of AR and AD, but not of asthma, have increased. The proportion of atopy has remained high. The AR/AD symptom rise is probably a consequence of increased pollen sensitisation united with high particulate matter concentrations. The stable asthma trend could be a result of decreasing exposures to indoor allergens.

Youth E-Cigarette Use and Functionally Important Respiratory Symptoms: The Population Assessment of Tobacco and Health (PATH) Study Waves 3 and 4

Respiratory effects of e-cigarette use among youth are not fully understood. This study investigated the longitudinal association between e-cigarette use and a validated index of functionally important respiratory symptoms among US youth. Data from Waves 3-4 of the Population Assessment of Tobacco and Health Study were analyzed. The sample included youth (aged 12-17) without asthma at baseline (Wave 3), who completed a follow-up survey (Wave 4), and were not missing data for analytic variables (n = 3899). Exposure was e-cigarette use status (never, former, or current) at baseline. The outcome was a respiratory symptom index based on responses for seven wheezing items at Wave 4. An index of ≥2 was defined as having functionally important respiratory symptoms. Lagged logistic regression models examined the association between baseline e-cigarette use and functionally important respiratory symptoms at follow-up by combustible tobacco use status (never or ever), and controlling for baseline covariates. At baseline, 13.7% of participants reported former e-cigarette use, and 4.3% reported current use. Baseline e-cigarette use did not increase the odds of having functionally important respiratory symptoms at follow-up regardless of combustible tobacco use status. Future research on larger populations of e-cigarette users with longer follow-up periods will improve our understanding of the respiratory risks associated with e-cigarette use among youth.

The Accuracy of a Screening Tool in Epidemiological Studies-An Example of Exhaled Nitric Oxide in Paediatric Asthma

Diagnostic tests are widely used in medicine, especially in the clinical setting. The doctor's decision regarding the treatment process is mostly based on the result of the diagnostic test. The value of the test is expressed by its accuracy. It is easier to verify the accuracy of a diagnostic test in a clinical setting in comparison to an epidemiological setting. Moreover, a very good test may not work in epidemiological settings in the same effective way as in a clinical setting, especially because the accuracy is affected by the prevalence of the disease. The aim of the study is to assess the accuracy of FeNO measurement in different respiratory disorders or symptoms, including their prevalence, in a childhood population. The secondary aim is to suggest the optimal FeNO cut-off for epidemiological screening for respiratory diseases and symptoms.

METHODS

The cross-sectional study included 447 children (50.8% boys and 49.2% girls) aged 6-9 years. An adapted version of the ISAAC questionnaire was used for the assessment of the respiratory status. FeNO was measured with an electrochemical device (Niox Mino) according to ERS/ATS recommendations. For interpretation, the FeNO cut-off values of 20 parts per billion (ppb), 25 ppb and 35 ppb were applied taking the real-life prevalence of the disease or symptoms into consideration and also for simulated prevalences of 20%, 30%, 40%, 50% for the interpretation of the accuracy of the test. The accuracy was calculated according to the following formula: Accuracy = (Prevalence) (Sensitivity) + (1- Prevalence) (Specificity). The area under the curve was calculated based on logistic regression.

RESULTS

For all respiratory outcomes, FeNO accuracy decreased with increasing prevalence, and in general the area under the curve (AUC) was low. The highest FeNO accuracy was found for any asthma diagnosis (with possible coexisting diseases/symptoms), i.e., 78.6%, 92.8% and 88.5% for FeNO cut-offs >19 ppb, >24 ppb and >34 ppb, respectively. The AUC was 0.628. For the same FeNO cut-offs, the accuracy of an asthma diagnosis without any coexisting diseases and symptoms was 81.2%, 87.5%, 92.9%, respectively, with an AUC of 0.757.

CONCLUSION

FeNO accuracy decreases with increasing prevalence of the respiratory disease and symptoms. The best accuracy for the FeNO cut-off in the screening of asthma for epidemiological purposes is 35 ppb. For isolated asthma, the best accuracy for FeNO was 92.9%.

Parental Knowledge about Allergies and Problems with an Elimination Diet in Children Aged 3 to 6 Years

Allergic diseases are highly prevalent, and they can exert a significant influence on the patients’ physical and mental well-being, thus affecting the quality of their lives and society as a whole. The aim of this study was to evaluate parental knowledge about allergens, allergy symptoms, and treatment of allergies, and to identify problems with adherence to an elimination diet and the underlying difficulties. Twelve kindergartens and the parents of 1350 preschoolers took part in the first stage of the study. In a screening trial, allergies were diagnosed in 197 children, and their parents participated in the second stage of the study. The child’s age at the onset of the first symptoms was significantly correlated with allergy type. Age was significantly correlated with selected symptoms of an allergic reaction, and skin allergies were more prevalent in younger children. Erythema, skin reddening, and urticaria occurred more frequently in children aged 3−4 years (OR 1.45; 95%CI 1.24−1.77, p < 0.05) and were diagnosed in skin tests (OR 1.36; 95%CI 1.22−1.59, p < 0.05). Allergies to numerous food items were associated with a long-term elimination diet (OR 1.89; 95%CI 1.33−2.19, p < 0.01), as well as problems with preparing safe meals, shopping for food, or dietary adherence when eating out. According to the respondents, lack of support from other family members and compliance with dietary restrictions in kindergartens and when eating out posed the greatest barriers to dietary adherence. Parents do not have sufficient knowledge about environmental allergens and effective strategies for coping with acute allergic reactions, including anaphylactic shock. Children with diagnosed food allergies should enjoy a similar quality of life to their healthy peers, which is why the parents should be educated about diet therapy, duration of treatment, and safe food substitutes.

The associations between residential greenness and allergic diseases in Chinese toddlers: A birth cohort study

BACKGROUND

Green space in the living environment has been linked to the development of allergic diseases. However, evidence regarding early-onset allergy in toddlers was limited, and the critical exposure window remained unclear. We aimed to investigate associations between residential greenness with allergic diseases in early life.

METHODS

This prospective birth cohort study included 522 mother-child pairs in Guangzhou, China. We quantified prenatal, postnatal, and early-life (i.e., the first 1000 days of life) residential greenness, estimated from remote satellite data using normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), and tree cover. We identified physician-diagnosed allergic diseases (eczema, atopic dermatitis, urticaria, allergic rhinitis, allergic conjunctivitis, food allergy, and asthma) based on medical records at age 2 years. Generalized linear regression was conducted to examine the associations of greenness with allergic outcomes.

RESULTS

The ranges of residential NDVI and EVI values in 500-m buffer during early life were 0.06-0.70 and 0.03-0.46, respectively. We found a 0.1 unit increase of NDVI in 500-m buffer throughout early life was associated with higher odds of any allergic diseases (prenatal: OR [odds ratio], 1.25; 95%CI, 1.02-1.53; postnatal: OR, 1.24; 95%CI, 1.02-1.52; early-life: OR, 1.25, 95%CI: 1.02-1.53) and higher odds of eczema (prenatal: OR, 1.28; 95%CI, 1.04-1.59; postnatal: OR, 1.24; 95%CI, 1.01-1.54; early-life: OR, 1.26, 95%CI: 1.02-1.56). The results were consistent when using EVI as a proxy for greenness. We only observed that prenatal exposure to the highest tertile of NDVI-500 was adversely associated with any allergic diseases (OR, 1.63; 95%CI, 1.03-2.58) and eczema (OR, 1.70; 95%CI: 1.04-2.78) compared with the lowest tertile.

CONCLUSIONS

This study identified detrimental associations of residential greenness with allergic diseases especially eczema among toddlers, and pregnancy appears to be the critical exposure window. Our findings highlighted the importance of urban planning to develop friendly-green neighborhood to improve maternal and child health.

The burden of asthma among children and adolescents in Saudi Arabia: A national cross-sectional survey

Background

Asthma disease is one of the most common chronic diseases of childhood. Studies assessing asthma prevalence in Saudi Arabia have been variable and not recently updated.

Objectives

We sought to assess asthma prevalence, severity, and related risk factors among children and adolescents in Saudi Arabia.

Methods

A national, cross-sectional design was used following the Global Asthma Network phase I design. A total of 3817 children aged 6 to 7 years and 4138 adolescents aged 13 to 14 years were recruited from 137 primary and 140 intermediate schools across 20 regions by using a multistage stratified cluster sampling technique. Standardized written questionnaires were answered by the adolescents and by the parents or guardians of the children. The adolescents also answered a video-based questionnaire.

Results

Overall, the prevalences of current wheeze were 10.4% and 13.3% and the prevalences of asthma ever were 13.8% and 15.7%, % in children and adolescents, respectively. Of all the children and adolescents, 5.2% and 5.6% had symptoms of severe asthma, respectively. Among those who reported asthma, 86.0% of the children and 74.8% of the adolescents had their asthma confirmed by a doctor, and 53.0% and 32.4%, respectively, were provided with a written plan to control their asthma. The main risk factors associated with current wheeze included antibiotic use in the first year of life, a history of being diagnosed with pneumonia in children, paracetamol use, and having a cat at home during the past 12 months in adolescents.

Conclusions

The prevalence of asthma in children and adolescents in Saudi Arabia is within the average international range and is at a plateau phase.

The critical importance of follow-up to school age: Contributions of the NICHD Neonatal Research Network

Follow-up studies are essential for understanding outcomes and informing the care of infants with high risk for medical and developmental consequences because of extreme prematurity or perinatal illness. Studies that extend to school age often identify sequelae that go unrecognized in neonatal or short-term follow-up studies. Many critical neurocognitive, behavioral, functional, and health outcomes are best assessed beginning at school age. The Eunice Kennedy Shriver National Institute of Child Health and Development Neonatal Research Network (NRN) has performed comprehensive school age evaluations of several key trial cohorts. This manuscript summarizes the important contributions of school age follow-up studies in the NRN, both historically and in ongoing research. We describe in detail the clinical questions that have been answered by the completed studies and new questions about the outcomes of high-risk infants that must be addressed by ongoing and future studies.

Phthalate Metabolites in Urine of Chinese Children and Their Association with Asthma and Allergic Symptoms

Phthalates are ubiquitous 'modern' chemical compounds with potential negative impacts on children's health. A nested case-control study was designed to investigate associations of phthalate exposure with children's asthma and allergic symptoms. We collected 243 first morning urine samples from 4-8-year-old children in Tianjin, China. Eight metabolites (i.e., mono-ethyl phthalate (MEP), mono-isobutyl phthalate (MiBP), mono-n-butyl phthalate (MnBP), mono-benzyl phthalate (MBzP) and mono-2-ethylhexyl phthalate (MEHP), mono-(2-ethyl-5-carboxylpentyl) phthalate (MECPP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP)) of five phthalates were analyzed using HPLC-MS. MiBP, MnBP and MECPP were the dominant phthalate metabolites in urine of children in Tianjin with median concentrations of 31.6 μg/L, 26.24 μg/L and 46.12 μg/L, respectively. We found significantly positive associations of diagnosed asthma with MnBP (adjusted odds ratios (AOR): 1.96; 95% confidence intervals (CIs): 1.07-3.61), MEHHP (AOR: 2.00; 95% CI: 1.08-3.71) and MEOHP (AOR: 2.09; 95% CI: 1.06-4.10). Our study indicates that phthalate exposure in childhood, especially to di-n-butyl phthalate (DnBP) and di(2-ethylhexyl) phthalate (DEHP), may be a risk factor for children's asthma.

Biomass Smoke Exposure and Atopy among Young Children in the Western Highlands of Guatemala: A Prospective Cohort Study

Women and children in rural regions of low-income countries are exposed to high levels of household air pollution (HAP) as they traditionally tend to household chores such as cooking with biomass fuels. Early life exposure to air pollution is associated with aeroallergen sensitization and developing allergic diseases at older ages. This prospective cohort study assigned HAP-reducing chimney stoves to 557 households in rural Guatemala at different ages of the study children. The children's air pollution exposure was measured using personal CO diffusion tubes. Allergic outcomes at 4-5 years old were assessed using skin prick tests and International Study of Asthma and Allergies in Childhood (ISAAC)-based questionnaires. Children assigned to improved stoves before 6 months old had the lowest HAP exposure compared to the other groups. Longer exposure to the unimproved stoves was associated with higher risks of maternal-reported allergic asthma (OR = 2.42, 95% CI: 1.11-5.48) and rhinitis symptoms (OR = 2.01, 95% CI: 1.13-3.58). No significant association was found for sensitization to common allergens such as dust mites and cockroaches based on skin prick tests. Reducing HAP by improving biomass burning conditions might be beneficial in preventing allergic diseases among children in rural low-income populations.

Cohort profile: the ECHO prenatal and early childhood pathways to health consortium (ECHO-PATHWAYS)

PURPOSE

Exposures early in life, beginning in utero, have long-term impacts on mental and physical health. The ECHO prenatal and early childhood pathways to health consortium (ECHO-PATHWAYS) was established to examine the independent and combined impact of pregnancy and childhood chemical exposures and psychosocial stressors on child neurodevelopment and airway health, as well as the placental mechanisms underlying these associations.

PARTICIPANTS

The ECHO-PATHWAYS consortium harmonises extant data from 2684 mother-child dyads in three pregnancy cohort studies (CANDLE [Conditions Affecting Neurocognitive Development and Learning in Early Childhood], TIDES [The Infant Development and Environment Study] and GAPPS [Global Alliance to Prevent Prematurity and Stillbirth]) and collects prospective data under a unified protocol. Study participants are socioeconomically diverse and include a large proportion of Black families (38% Black and 51% White), often under-represented in research. Children are currently 5-15 years old. New data collection includes multimodal assessments of primary outcomes (airway health and neurodevelopment) and exposures (air pollution, phthalates and psychosocial stress) as well as rich covariate characterisation. ECHO-PATHWAYS is compiling extant and new biospecimens in a central biorepository and generating the largest placental transcriptomics data set to date (N=1083).

FINDINGS TO DATE

Early analyses demonstrate adverse associations of prenatal exposure to air pollution, phthalates and maternal stress with early childhood airway outcomes and neurodevelopment. Placental transcriptomics work suggests that phthalate exposure alters placental gene expression, pointing to mechanistic pathways for the developmental toxicity of phthalates. We also observe associations between prenatal maternal stress and placental corticotropin releasing hormone, a marker of hormonal activation during pregnancy relevant for child health. Other publications describe novel methods for examining exposure mixtures and the development of a national spatiotemporal model of ambient outdoor air pollution.

FUTURE PLANS

The first wave of data from the unified protocol (child age 8-9) is nearly complete. Future work will leverage these data to examine the combined impact of early life social and chemical exposures on middle childhood health outcomes and underlying placental mechanisms.

Tobacco Use and Respiratory Symptoms Among Adults: Findings From the Longitudinal Population Assessment of Tobacco and Health (PATH) Study 2014-2016

INTRODUCTION

We examined the relationship between current tobacco use and functionally important respiratory symptoms.

METHODS

Longitudinal cohort study of 16 295 US adults without COPD in Waves 2-3 (W2-3, 2014-2016) of the Population Assessment of Tobacco and Health Study. Exposure-Ten mutually exclusive categories of tobacco use including single product, multiple product, former, and never use (reference). Outcome-Seven questions assessing wheezing/cough were summed to create a respiratory symptom index; cutoffs of ≥2 and ≥3 were associated with functional limitations and poorer health. Multivariable regressions examined both cutoffs cross-sectionally and change over approximately 12 months, adjusting for confounders.

RESULTS

All tobacco use categories featuring cigarettes (>2/3's of users) were associated with higher risk (vs. never users) for functionally important respiratory symptoms at W2, for example, at symptom severity ≥ 3, risk ratio for exclusive cigarette use was 2.34 [95% CI, 1.92, 2.85] and for worsening symptoms at W3 was 2.80 [2.08, 3.76]. There was largely no increased symptom risk for exclusive use of cigars, smokeless tobacco, hookah, or e-cigarettes (adjustment for pack-years and marijuana attenuated the cross-sectional e-cigarette association from 1.53(95% CI 0.98, 2.40) to 1.05 (0.67, 1.63); RRs for these products were also significantly lower compared to exclusive use of cigarettes. The longitudinal e-cigarette-respiratory symptom association was sensitive to the respiratory index cutoff level; exclusive e-cigarette use was associated with worsening symptoms at an index cutoff ≥ 2 (RR = 1.63 [1.02, 2.59]) and with symptom improvement at an index cutoff of ≥ 3 (RR = 1.64 [1.04, 2.58]).

CONCLUSIONS

Past and current cigarette smoking drove functionally important respiratory symptoms, while exclusive use of other tobacco products was largely not associated. However, the relationship between e-cigarette use and symptoms was sensitive to adjustment for pack-years and symptom severity.

IMPLICATIONS

How noncigarette tobacco products affect respiratory symptoms is not clear; some studies implicate e-cigarettes. We examined functionally important respiratory symptoms (wheezing/nighttime cough) among US adults without COPD. The majority of adult tobacco users smoke cigarettes and have higher risk of respiratory symptoms and worsening of symptoms, regardless of other products used with them. Exclusive use of other tobacco products (e-cigarettes, cigars, smokeless, hookah) was largely not associated with functionally important respiratory symptoms and risks associated with their use was significantly lower than for cigarettes. The association for e-cigarettes was greatly attenuated by adjustment for cigarette pack-years and sensitive to how symptoms were defined.

Associations of Early-Life Exposure to Submicron Particulate Matter With Childhood Asthma and Wheeze in China

IMPORTANCE

Exposure to particulate matter (PM) has been associated with childhood asthma and wheeze. However, the specific associations between asthma and PM with an aerodynamic equivalent diameter of 1 μm or less (ie, PM1), which is a contributor to PM2.5 and potentially more toxic than PM2.5, remain unclear.

OBJECTIVE

To investigate the association of early-life (prenatal and first year) exposure to size-segregated PM, including PM1, PM1-2.5, PM2.5, PM2.5-10, and PM10, with childhood asthma and wheeze.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study was based on a questionnaire administered between June 2019 and June 2020 to caregivers of children aged 3 to 6 years in 7 Chinese cities (Wuhan, Changsha, Taiyuan, Nanjing, Shanghai, Chongqing, and Urumqi) as the second phase of the China, Children, Homes, Health study.

EXPOSURES

Exposure to PM1, PM1-2.5, PM2.5, PM2.5-10, and PM10 during the prenatal period and first year of life.

MAIN OUTCOMES AND MEASURES

The main outcomes were caregiver-reported childhood asthma and wheeze. A machine learning-based space-time model was applied to estimate early-life PM1, PM2.5, and PM10 exposure at 1 × 1-km resolution. Concentrations of PM1-2.5 and PM2.5-10 were calculated by subtracting PM1 from PM2.5 and PM2.5 from PM10, respectively. Multilevel (city and child) logistic regression models were applied to assess associations.

RESULTS

Of 29 418 children whose caregivers completed the survey (15 320 boys [52.1%]; mean [SD] age, 4.9 [0.9] years), 2524 (8.6%) ever had wheeze and 1161 (3.9%) were diagnosed with asthma. Among all children, 18 514 (62.9%) were breastfed for more than 6 months and 787 (2.7%) had parental history of atopy. A total of 22 250 children (75.6%) had a mother with an educational level of university or above. Of the 25 422 children for whom information about cigarette smoking exposure was collected, 576 (2.3%) had a mother who was a current or former smoker during pregnancy and 7525 (29.7%) had passive household cigarette smoke exposure in early life. Early-life PM1, PM2.5, and PM10 exposure were significantly associated with increased risk of childhood asthma, with higher estimates per 10-μg/m3 increase in PM1 (OR, 1.55; 95% CI, 1.27-1.89) than in PM2.5 (OR, 1.14; 95% CI, 1.03-1.26) and PM10 (OR, 1.11; 95% CI, 1.02-1.20). No association was observed between asthma and PM1-2.5 exposure, suggesting that PM1 rather than PM1-2.5 contributed to the association between PM2.5 and childhood asthma. There were significant associations between childhood wheeze and early-life PM1 exposure (OR, 1.23; 95% CI, 1.07-1.41) and PM2.5 exposure (OR, 1.08; 95% CI, 1.01-1.16) per 10-μg/m3 increase in PM1 and PM2.5, respectively.

CONCLUSIONS AND RELEVANCE

In this cross-sectional study, higher estimates were observed for the association between PM with smaller particles, such as PM1, vs PM with larger particles and childhood asthma. The results suggest that the association between PM2.5 and childhood asthma was mainly attributable to PM1.

The association between hypertensive disorders of pregnancy and childhood asthma

BACKGROUND

Asthma is a chronic long-term inflammatory disease of the airways and is a major global health challenge. The primary aim of this study was to investigate the association between hypertensive disorders of pregnancy (HDP) and the risk of asthma at or before the age of seven years using the UK Millennium Cohort Study (MCS).

METHODS

Overall, 18,552 families were recruited for wave one of the MCS when the child was 9 months old, and subsequently participated in waves two, three and four when they were three, five and seven years respectively. HDP were self-reported by mothers in wave one. The primary outcome was a parent-reported diagnosis of "ever asthma" at seven years, based on responses to a validated questionnaire.

RESULTS

Following adjustment for a range of potential confounding factors, HDP was found to be associated with asthma in the offspring (adjusted odds ratio (AOR 1.35; 95% CI: 1.15-1.59)). A larger effect estimate was observed amongst children exposed to HDP and born preterm (AOR 1.81; 95% CI: 1.25-2.61) or small for gestational age (SGA) (AOR = 1.58; (95% CI: 1.15-2.18)).

CONCLUSIONS

In conclusion, children exposed to HDP may be at increased odds of asthma diagnosis by age seven, particularly if they were born preterm or SGA.

IMPACT

There is a paucity of data investigating the relationship between hypertensive disorders of pregnancy and childhood asthma, with recent studies showing conflicting results. Our study investigated this relationship using a large cohort with ample information on a wide range of confounding factors. Our study showed that individuals exposed to HDP may be at increased odds of asthma diagnosis by age seven years, particularly if they were also born SGA or preterm.

Early-life respiratory tract infections and the risk of school-age lower lung function and asthma: a meta-analysis of 150 000 European children

BACKGROUND

Early-life respiratory tract infections might affect chronic obstructive respiratory diseases, but conclusive studies from general populations are lacking. Our objective was to examine if children with early-life respiratory tract infections had increased risks of lower lung function and asthma at school age.

METHODS

We used individual participant data of 150 090 children primarily from the EU Child Cohort Network to examine the associations of upper and lower respiratory tract infections from age 6 months to 5 years with forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), FEV1/FVC, forced expiratory flow at 75% of FVC (FEF75%) and asthma at a median (range) age of 7 (4-15) years.

RESULTS

Children with early-life lower, not upper, respiratory tract infections had a lower school-age FEV1, FEV1/FVC and FEF75% (z-score range: -0.09 (95% CI -0.14- -0.04) to -0.30 (95% CI -0.36- -0.24)). Children with early-life lower respiratory tract infections had a higher increased risk of school-age asthma than those with upper respiratory tract infections (OR range: 2.10 (95% CI 1.98-2.22) to 6.30 (95% CI 5.64-7.04) and 1.25 (95% CI 1.18-1.32) to 1.55 (95% CI 1.47-1.65), respectively). Adjustment for preceding respiratory tract infections slightly decreased the strength of the effects. Observed associations were similar for those with and without early-life wheezing as a proxy for early-life asthma.

CONCLUSIONS

Our findings suggest that early-life respiratory tract infections affect development of chronic obstructive respiratory diseases in later life, with the strongest effects for lower respiratory tract infections.

Associations between home renovation and asthma, allergic rhinitis, and eczema among preschool children in Wuhan, China

To investigate the potential associations between household renovation and allergic diseases among preschool children in Wuhan, we conducted a large cross-sectional questionnaire survey among 9455 preschool children aged 3-6 years in Wuhan during November to December 2019. Data on demographics, health status, and home decoration conditions were analysed based on a questionnaire. Compared with tiles/stone/cement floor covering, the use of composite floor significantly increased the risk of diagnosed rhinitis and eczema among children (rhinitis: AOR, 95% CI: 1.36, 1.06-1.73; eczema: AOR, 95% CI: 1.47, 1.17-1.85). Household renovation had significant associations with diagnosed eczema (within 1 year before pregnancy: AOR, 95% CI: 1.34, 1.20-1.50; during pregnancy: AOR, 95% CI: 1.25, 1.08-1.44). This study suggests that use of artificial synthetic materials in home renovation during early childhood and pregnancy may be potential risk factors for childhood asthma, allergic rhinitis, and eczema.

Sex specific associations between in utero exposure to persistent organic pollutants and allergy-related outcomes in childhood: The Rhea Mother-Child Cohort (Crete, Greece)

Accumulating evidence suggests that in utero exposures can influence the development of the immune system. Few studies have investigated whether prenatal exposure to persistent organic pollutants (POPs) is associated with allergy-related phenotypes in childhood, nor explored sex differences. We examined the association between prenatal exposure to POPs and offspring allergic outcomes in early and mid-childhood. We included 682 mother-child pairs from the prospective birth cohort Rhea. We measured dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB) and 6 polychlorinated biphenyl (PCB) congeners in maternal first trimester serum. Parents completed the questionnaires adapted from the International Study on Asthma and Allergy in Childhood (ISAAC) for allergy-related phenotypes when their children were 4 and 6 years old. We used Poisson regression models to estimate Risk Ratios. Prenatal HCB was associated with increased risk for rhinoconjunctivitis at 6 years (RR (95% CI): 2.5; (1.3, 4.8) for a doubling in the exposure). Among girls, prenatal DDE was associated with increased risk for current wheeze, current asthma and current rhinoconjunctivitis at 4 years (RR (95%CI): 1.4 (0.8, 2.6), 1.6 (1.1, 2.4) and 1.8 (1.0, 3.3) and p-interaction = 0.035, 0.027 and 0.059, respectively), with increased risk for current rhinoconjunctivitis at 6 years (RR (95%CI): 1.7 (0.7, 3.8) and p-interaction = 0.028) and total PCBs were associated with increased risk for current eczema at 4 years (RR (95%CI): 2.1 (1.1, 4.2) and p-interaction = 0.028). In boys, prenatal DDE was associated with decreased risk for current wheeze and current asthma at 4 years. Our findings suggest that even low levels of exposure to POPs prenatally may affect the development of childhood allergy-related outcomes in a sex and age-specific manner.

The Effect of Obesity on Fractional Exhaled Nitric Oxide in School-Aged Children

Background: Fractional exhaled nitric oxide (FeNO) is recognized as a biomarker of eosinophilic inflammation. Current literature shows evidence that FeNO is influenced by many factors. Obesity is a chronic inflammatory state. In this study, we considered obesity as a potential factor that influences FeNO levels. The aim of the study was to analyze the association between body mass index (BMI, body mass (kg)/height (m)2) and FeNO levels in a young group of children. Methods: The participants in the study were 506 school-aged children who were randomly selected from primary schools located in Silesian Voivodship (Poland). The modified version of the Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was used to assess the respiratory system status of children. FeNO was measured in 447 children according to European Respiratory Society and America Thoracic Society (ERS/ATS) recommendations. Body mass and height were measured by a medical body composition analyzer. BMI was defined and interpreted with Palczewska’s percentile charts. Results: In the study group there were 49.9% (n = 223) boys and 50.1% (n = 224) girls. The frequency of normal BMI was 76.8% (n = 172), overweight 13.7% (n = 31) and obesity 9.4% (n = 21) in girls, while the normal BMI was found in 71.3% (n = 159), overweight 11.6% (n = 26) and obesity 17% (n = 38) in boys, the differences not statistically significant (p = 0.05). The mean FeNO value in children with obesity was 16.1 ± 12.5 ppb, in children with normal BMI 15.8 ± 15.5 ppb and the lowest FeNO values were in children with overweight 15.3 ± 13.0 ppb; p = 0.9. The FeNO values after adjusting for age, sex, BMI and symptoms from respiratory system were depended on age and respiratory symptoms only. Conclusions: In 6–9 year old school children, FeNO levels are associated with age and health in relation to the respiratory system. The BMI should not be included when considering reference values for FeNO.

Arsenic exposure and respiratory outcomes during childhood in the INMA study

Ingested inorganic arsenic (iAs) is a human carcinogen that is also linked to other adverse health effects, such as respiratory outcomes. Yet, among populations consuming low-arsenic drinking water, the impact of iAs exposure on childhood respiratory health is still uncertain. For a Spanish child study cohort (INfancia y Medio Ambiente—INMA), low-arsenic drinking water is usually available and ingestion of iAs from food is considered the major source of exposure. Here, we explored the association between iAs exposure and children’s respiratory outcomes assessed at 4 and 7 years of age (n = 400). The summation of 4-year-old children’s urinary iAs, monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) was used as a biomarker of iAs exposure (∑As) (median of 4.92 μg/L). Children’s occurrence of asthma, eczema, sneeze, wheeze, and medication for asthma and wheeze at each assessment time point (i.e., 4- and 7-year) was assessed with maternal interviewer-led questionnaires. Crude and adjusted Poisson regression models using Generalized Estimating Equation (GEE) were performed to account for the association between natural logarithm transformed (ln) urinary ∑As in μg/L at 4 years and repeated assessments of respiratory symptoms at 4 and 7 years of age. The covariates included in the models were child sex, maternal smoking status, maternal level of education, sub-cohort, and children’s consumption of vegetables, fruits, and fish/seafood. The GEE—splines function using Poisson regression showed an increased trend of the overall expected counts of respiratory symptoms with high urinary ∑As. The adjusted expected counts (95% confidence intervals) at ln-transformed urinary ∑As 1.57 (average concentration) and 4.00 (99^th percentile concentration) were 0.63 (0.36, 1.10) and 1.33 (0.61, 2.89), respectively. These exploratory findings suggest that even relatively low-iAs exposure levels, relevant to the Spanish and other populations, may relate to an increased number of respiratory symptoms during childhood.

12-month prevalence of atopic dermatitis in resource-rich countries: a systematic review and meta-analysis

There is a lack of robust prevalence estimates of atopic dermatitis (AD) globally and trends over time due to wide variation of populations and age groups studied, different study methodologies and case definitions used. We sought to characterize 12-month AD prevalence across the life span and change over time in resource-rich countries focusing on population-based studies and using a standardized AD case definition. This systematic review was conducted according to PRISMA guidelines. Medline (Ovid), Embase, WOS core collection, Cinahl, and Popline were searched for studies published since inception through August 15, 2016. Studies were synthesized using random effects meta-analysis. Sources of heterogeneity were investigated using subgroup analyses and meta-regression. From 12,530 records identified, 45 studies met the inclusion criteria. Meta-analysis with random effects revealed the 12-month period prevalence of 9.2% (95% confidence interval 8.4-10.1%). The prevalence was significantly higher among 0-5-year-old children (16.2%; 95% confidence interval 14.2-18.7%) than in older age groups. Studies using a random sampling strategy yielded lower prevalence estimates than studies relying on other sampling methods. There was no clear time trend in AD prevalence over the period of 1992-2013.

Characteristics of annual mold variations and association with childhood allergic symptoms/diseases via combining surveys and home visit measurements

The presence of dampness and visible molds leads to concerns of poor indoor air quality which has been consistently linked with increased exacerbation and development of allergy and respiratory diseases. Due to the limitations of epidemiological surveys, the actual fungal exposure characteristics in residences has not been sufficiently understood. This study aimed to characterize household fungal diversity and its annual temporal and spatial variations. We developed combined cross-sectional survey, repeated air sampling around a year, and DNA sequencing methods. The questionnaire survey was conducted in 2019, and 4943 valid cases were received from parents; a follow-up case-control study (11 cases and 12 controls) was designed, and onsite measurements of indoor environments were repeated in typical summer, transient season, and winter; dust from floor and beddings in children's room were collected and ITS based DNA sequencing of totally 68 samples was conducted. Results from 3361 children without changes to their residences since birth verified the significant associations of indoor dampness/mold indicators and prevalence of children-reported diseases, with increased adjusted odd ratios (aORs) >1 for studied asthma, wheeze, allergic rhinitis, and eczema. The airborne fungal concentrations from air sampling were higher than 1000 CFU/m³ in summer, regardless of indoors and outdoors, indicating an intermediate pollution level. The DNA sequencing for dust showed the Aspergillus was the predominant at genus level and the Aspergillus_penicillioides was the most common at species level; while the fungal community and composition varied significantly in different homes and seasons, according to α and β diversity analyses. The comprehensive research methods contribute to a holistic understanding of indoor fungal exposure, including the concentrations, seasonal variations, community, and diversity, and verifies the relations with children's adverse health outcomes. The study further elucidates the role of microbiome in human health, which helps setting health-protective thresholds and managing mold treatments in buildings, to promote indoor air quality and human well-beings.

Disadvantage in early-life and persistent asthma in adolescents: a UK cohort study

OBJECTIVE

To determine how early-life risk factors explain socioeconomic inequalities in persistent asthma in adolescence.

METHODS

We did a causal mediation analysis using data from 7487 children and young people in the UK Millennium Cohort Study. Persistent asthma was defined as having a diagnosis reported at any two or more time points at 7, 11 or 14 years. The main exposure was maternal education, a measure of early-life socioeconomic circumstances (SECs), used to calculate the relative index of inequality. We assessed how blocks of perinatal (maternal health behaviours, infant characteristics and duration of breastfeeding, measured at 9 months) and environmental risk factors (family housing conditions; potential exposure to infections through childcare type and sibling number, and neighbourhood characteristics, measured at 3 years) mediated the total effect of childhood SECs on persistent asthma risk, calculating the proportion mediated and natural indirect effect (NIE) via blocks of mediators.

RESULTS

At age 14 the overall prevalence of persistent asthma was 15%. Children of mothers with lower educational qualifications were more likely to have persistent asthma, with a clear social gradient (degree plus: 12.8% vs no qualifications: 20.3%). The NIE gives the effect of SECs acting only via the mediators and shows a 31% increased odds of persistent asthma when SECs are fixed at the highest level, and mediators at the level which would naturally occur at the lowest SECs versus highest SECs (NIE OR 1.31, 95% CI 1.04 to 1.65). Overall, 58.9% (95% CI 52.9 to 63.7) of the total effect (OR 1.70, 95% CI 1.20 to 2.40) of SECs on risk of persistent asthma in adolescence was mediated by perinatal and environmental characteristics.

CONCLUSIONS

Perinatal characteristics and the home environment in early life are more important in explaining socioeconomic inequalities in persistent asthma in British adolescents than more distal environmental exposures outside the home.

Impaired exercise outcomes with significant bronchodilator responsiveness in children with prematurity-associated obstructive lung disease

INTRODUCTION

Preterm-born children have their normal in-utero lung development interrupted, thus are at risk of short- and long-term lung disease. Spirometry and exercise capacity impairments have been regularly reported in preterm-born children especially those who developed chronic lung disease of prematurity (CLD) in infancy. However, specific phenotypes may be differentially associated with exercise capacity. We investigated exercise capacity associated with prematurity-associated obstructive (POLD) or prematurity-associated preserved ratio of impaired spirometry (pPRISm) when compared to preterm- and term-controls with normal lung function.

MATERIALS AND METHODS

Preterm- and term-born children identified through home screening underwent in-depth lung function and cardiorespiratory exercise testing, including administration of postexercise bronchodilator, as part of the Respiratory Health Outcomes in Neonates (RHiNO) study.

RESULTS

From 241 invited children, aged 7-12 years, 202 underwent exercise testing including 18 children with POLD (percent predicted (%)FEV₁ and FEV₁ /FVC < LLN); 12 pPRISm (%FEV₁  < LLN and FEV₁ /FVC ≥ LLN), 106 preterm-controls (PT_c , %FEV₁  ≥ LLN) and 66 term-controls (T_c , %FEV₁  > 90%). POLD children had reduced relative workload, peak O₂ uptake, CO₂ production, and minute ventilation compared to T_c , and used a greater proportion of their breathing reserve compared to both control groups. pPRISm and PT_c children also had lower O₂ uptake compared to T_c . POLD children had the greatest response to postexercise bronchodilator, improving their %FEV₁ by 19.4% (vs 6.3%, 6% 6.3% in pPRISm PT_c, T_c , respectively; p < .001).

CONCLUSION

Preterm-born children with obstructive airway disease had the greatest impairment in exercise capacity, and significantly greater response to postexercise bronchodilators. These classifications can be used to guide treatment in children with POLD.

Reference values for respiratory sinusoidal oscillometry in children aged 3 to 17 years

BACKGROUND

New oscillometry devices allowing quantification of respiratory function using tidal breathing are commercially available, but reference equations are lacking for the multiethnic Canadian pediatric population.

METHODS

We conducted a prospective cross-sectional study of healthy children carefully selected for absence of asthma, atopy, tobacco smoke, obesity, prematurity, and recent respiratory infection. Triplicate measures were obtained of respiratory system resistance (Rrs) and reactance (Xrs), area under the reactance curve (AX) and resonant frequency (Fres) on four signals, whose testing order was randomized: two signals on the Resmon Pro Full (8 Hz and 5-11-19 Hz) and two signals on the tremoflo C-100 (5-37 Hz and 7-41 Hz). Feasibility was defined as the ability to obtain valid reproducible results. Prediction equations and 95% confidence intervals were derived for whole- and within-breath Rrs and Xrs and for AX and Fres, using linear regression or Generalized Additive Models for Location, Scale and Shape.

RESULTS

Of 306 children randomized, valid and reproducible results on ≥1 signal were obtained in 299 (98%) multiethnic (69% Caucasians: 8% Black: 23% Others) children aged 3-17 years, 91-189 cm tall. Standing height was the strongest predictor with no significant effect of sex, age, body mass index or ethnicity. Significant within-patient differences were observed between Resmon Pro and tremoflo C-100 measurements, justifying the derivation of device-specific reference equations.

CONCLUSION

Valid reproducible oscillometry measurements are highly feasible in children aged 3 years and older. Device-specific reference equations, valid for our multiethnic population, are derived.

Maternal dietary folate intake with folic acid supplements and wheeze and eczema in children aged 2 years in the Japan Environment and Children’s Study

Maternal intake of folic acid supplements is reportedly associated with the risk of early-onset allergies in offspring. However, only a few studies have considered the intake of both folic acid supplements and dietary folate. Here, the relationship between maternal intake of folic acid supplements and allergic symptoms such as wheeze and eczema in offspring was analyzed while considering dietary folate intake. We examined 84,361 mothers and 85,114 children in the Japan Environment and Children’s Study. The participants were divided into three groups depending on maternal folic acid supplementation (“no use,” “occasional use,” and “daily use”). Each group was then subdivided into three groups based on total folic acid and dietary folate intake. Outcomes were determined considering the wheeze and eczema status of each child at the age of 2 years. The status was based on the International Study of Asthma and Allergies in Childhood. It was found that 22.1% of the mothers took folic acid supplements daily. In contrast, 56.3% of the mothers did not take these supplements. Maternal intake of folic acid supplements was not associated with wheeze and eczema in the offspring. In contrast, only dietary folate intake was positively associated with wheeze at the age of 2 (adjusted odds ratio, 1.103; 95% confidence interval, 1.003–1.212). However, there is no scientific evidence of a biological mechanism that clarifies this result. Potential confounders such as other nutrition, outdoor/indoor air pollution, and genetic factors may have affected the results. Therefore, further studies on the association between maternal intake of folic acid and allergic symptoms at the age of 3 or above are needed to confirm the results of this study.

Trial registration

UMIN Clinical Trials Registry (number: UMIN000030786)

The association between prenatal F2-isoprostanes and child wheeze/asthma and modification by maternal race

BACKGROUND

Childhood wheeze, asthma, and allergic rhinitis are common and likely have prenatal origins. Oxidative stress is associated with respiratory disease, but the association of oxidative stress during the prenatal period with development of respiratory and atopic disease in childhood, particularly beyond the infancy period, is unknown. This study aims to investigate associations between prenatal oxidative stress, measured by maternal urinary F2-isoprostanes, and child respiratory outcomes, including effect modification by maternal race.

METHODS

We prospectively studied Black (n = 717) and White (n = 363) mother-child dyads. We measured F2-isoprostanes in 2nd-trimester urine (ng/mg-creatinine). At approximately age 4, we obtained parent report of provider-diagnosed asthma (ever), current wheeze, current asthma (diagnosis, symptoms and/or medication), and current allergic rhinitis (current defined as previous 12 months). We used multivariable logistic regression to estimate adjusted odds ratios (aOR) and 95% confidence intervals (95%CI) per interquartile range (IQR) increase in F2-isoprostane concentration, controlling for confounders. We examined modification by maternal race using interaction terms.

RESULTS

The prevalence of provider-diagnosed asthma and current wheeze, asthma and allergic rhinitis was 14%, 19%, 15%, and 24%, respectively. Median (IQR) F2-isoprostane levels were 2.1 (1.6, 2.9) ng/mg-creatinine. Associations between prenatal F2-isoprostanes and provider-diagnosed asthma, current wheeze, and current asthma were modified by maternal race. Results were strongest for current wheeze (aOR [95%CI]: 1.55 [1.16, 2.06] for White; 0.98 [0.78, 1.22] for Black; p-interaction = 0.01). We observed no association between F2-isoprostanes and allergic rhinitis.

CONCLUSION

Prenatal urinary F2-isoprostanes may be a marker associated with childhood wheeze/asthma in certain populations. Research is needed to understand underlying mechanisms and racial differences.

A Questionnaire Survey on the Prevalence and Parents' Perceptions of Respiratory Allergies in a 3- to 16-Year-Old Population in Wuhan, China

(1) Background: The prevalence of allergic rhinitis (AR) and asthma has increased rapidly in China. However, perceptions of respiratory allergies and barriers to their management have not attracted enough attention. (2) Objective: To investigate the prevalence of, parents’ perceptions of and their unmet needs for information concerning respiratory allergies in a 3- to 16-year-old children population. (3) Methods: A cross-sectional survey was conducted from June to July 2021 in three schools in Wuhan, China. A total of 1963 participants were recruited through cluster sampling for their parents to complete an online questionnaire regarding respiratory allergic symptoms. The diagnosis of respiratory allergies was based on self-reported symptoms and face-to-face physician evaluation. All the participants with respiratory allergies were asked to complete the Brief Illness Perception Questionnaire (B-IPQ), the Asthma Knowledge Questionnaire (AKQ) and a questionnaire regarding their unmet needs for disease management. (4) Results: The prevalence of respiratory allergies was 29.3% (576/1963) in the 3- to 16-year-old population, among whom AR accounted for 25.7%; asthma, 1.8% and AR-complicated asthma (AR&Asthma), 1.9%. The total B-IPQ score was 40.2 ± 10.9 in the participants with respiratory allergies, and there were no differences among the AR, asthma and AR&Asthma groups (all p > 0.05). The B-IPQ score correlated significantly with symptom onset time and a history of atopic dermatitis (p < 0.01). Nearly one fifth, 18.9%, of the participants with respiratory allergies never went to hospital for treatment, but those with higher B-IPQ scores were more likely to seek professional treatment (p < 0.001). The accuracy rates of AKQ were 72.5% in the participants with asthma and 76.7% in those without asthma (p = 0.147). Among the 576 participants with respiratory allergies, 568 (98.6%) had tried to obtain disease-management information from online platforms, and 55.5% (315/568) were dissatisfied with current platforms; the reasons included incomprehensive contents of illness (45.7%), lack of voice from leading experts (40.3%), too many advertisements (37.5%) and similar contents on different platforms (36.8%). (5) Conclusions: The prevalence of respiratory allergies is high in the 3- to 16-years old population in Wuhan, China. Yet the parents’ perceptions of respiratory allergies and knowledge of asthma are insufficient. It is crucial to increase parents’ awareness of the illness and facilitate their access to truly informative and professional platforms.

Assessing the prevalence and severity of asthma, rhinitis, and eczema among schoolchildren (6-7 and 13-14 years old) in Khuzestan, Iran: a cross-sectional survey

Background

Asthma and allergic complications are the most common chronic disorders in children and adolescents. This study aimed to determine the prevalence and severity of asthma, allergic rhinitis, eczema among schoolchildren, and some related risk factors.

Methods

The cross-sectional study was performed in 2019 and involved 4000 students aged 6–7 years and 4000 students aged 13–14 years (both girls and boys) from urban schools in Khuzestan Province, southwestern Iran. We used the multi-stage sampling method. Data were collected using the Persian version of the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire.

Results

The prevalence of current wheeze, wheeze ever and asthma ever in the age group of 6–7 years was 3.8, 4.5, and 1.8%, respectively; in the age group of 13–14 years, it was 4.4, 5.9, and 3.4, respectively. In terms of gender, males (4.9, 6.0, and 2.7 percent, respectively) had substantially higher rates of current wheeze, wheeze ever, and asthma ever compared to the girls (2.8, 3.6, and 2.0 percent, respectively) (p < 0.001). The prevalence of rhinitis, Hay fever, and eczema among young people was 5.3%, 3.5%, and 1.0%, respectively. Current wheeze was more common in children with allergic rhinitis in the last 12 months (30.3% vs. 2.7%, p < 0.001), Hay fever (32.8% vs. 0.3%, p < 0.001) and eczema (27.8% vs 3.8%, p < 0.001), compared to children who did not.

Conclusions

The prevalence and severity of asthma symptoms were significantly associated with allergic rhinitis, eczema, and gender.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03520-x.

Tobacco Product Use and Functionally Important Respiratory Symptoms Among US Adolescents/Young Adults

OBJECTIVE

The relation between respiratory symptoms and the range of tobacco product use among US adolescents/young adults is not yet clear. This cross-sectional analysis examines tobacco product use and respiratory symptoms in a nationally representative sample of 21,057 adolescents/young adults aged 12-24 years from Wave 4 (2016-17) of the Population Assessment of Tobacco and Health Study.

METHODS

Presence of functionally important respiratory symptoms was defined by questions regarding wheezing and nighttime cough at a cutoff score associated with poorer functional health status. Past-30-day tobacco use was analyzed 2 ways: never-tobacco users (reference) versus combustible users, noncombustible-only users, and former users; or frequency of use of cigarettes and/or e-cigarettes. Weighted Poisson regression adjusted for past-30-day marijuana use, secondhand smoke exposure, and asthma.

RESULTS

Functionally important respiratory symptoms were present in 10.0% overall: 13.8% of combustible users, 9.0% of noncombustible users, 8.2% of noncurrent users and 9.7% of never users. Functionally important respiratory symptoms were associated with combustible tobacco use (relative risk [RR] = 1.52[95% CI 1.29, 1.80]), marijuana use (RR = 1.54[1.34, 1.77]) and secondhand smoke exposure (RR = 1.04[1.03, 1.05]). Higher cigarette smoking frequency was also associated with functionally important respiratory symptoms for frequency categories >14 days/month (eg, RR = 1.93[1.50, 2.49] for 15-29 days/month). Frequency of e-cigarette use was not associated with functionally important respiratory symptoms.

CONCLUSIONS

During 2016-17, smoking cigarettes, marijuana use, and secondhand smoke exposure were cross-sectionally associated with functionally important respiratory symptoms in adolescents/young adults. Risk increased with increased frequency of cigarette use but not e-cigarette use. Given changes to contemporary e-cigarettes and use, findings may not generalize to newer products.

Meconium-stained amniotic fluid during labor may be a protective factor for the offspring's childhood wheezing up to 3 years of age: the Japan Environment and Children's Study

We aimed to evaluate the association between meconium-stained amniotic fluid during labor and offspring's childhood wheezing. This study analyzed the data of participants enrolled in the Japan Environment and Children's Study, a nationwide prospective birth cohort study, between 2011 and 2014. Data of women with singleton live births between 22 and 40 weeks' gestation were analyzed. Participants were categorized into two groups according to the presence or absence of meconium-stained amniotic fluid. The primary outcome measure was the offspring's childhood wheezing up to 3 years of age. A logistic regression model was used to calculate the adjusted odds ratio for childhood wheezing in children of women with meconium-stained amniotic fluid, considering those without meconium-stained amniotic fluid as a reference, taking into account the potential confounding factors affecting the incidence of wheezing. We analyzed data from 61,991 participants: 1796 (2.9%) participants had meconium-stained amniotic fluid during labor and 18,919 (30.5%) of the offspring had childhood wheezing. The adjusted odds ratios for the offspring's childhood wheezing were 0.89 (95% confidence interval, 0.79-0.99) in total participants, 0.87 (95% confidence interval, 0.78-0.97) in term births, and 2.00 (95% confidence interval, 0.98-4.09) in preterm births.

CONCLUSIONS

This study revealed a decreased incidence of childhood wheezing among the children of women with meconium-stained amniotic fluid in term births. By yet unknown mechanisms, meconium-stained amniotic fluid was associated with a decreased incidence of childhood wheezing in the offspring. Further studies are required to clarify the mechanism of one's own meconium in affecting their health condition.

WHAT IS KNOWN

• Meconium-stained amniotic fluid during labor is associated with several adverse perinatal outcomes, and meconium aspiration syndrome is associated with offspring's childhood asthma and wheezing. • Meconium-stained amniotic fluid during labor could be an independent protective factor for the offspring's dermatitis and skin rash.

WHAT IS NEW

• Whole cases with meconium-stained amniotic fluid during labor were associated with a decreased incidence of offspring's childhood wheezing up to 3 years of age. • This study may shed light on the effects of simple meconium-stained amniotic fluid on offspring's childhood health.

The association between duration of breastfeeding and childhood asthma outcomes

BACKGROUND

Postnatal exposures, including breastfeeding, may influence asthma development.

OBJECTIVE

To investigate the association between breastfeeding duration and child asthma.

METHODS

We studied 2021 mother-child dyads in the ECHO PATHWAYS consortium of prospective pregnancy cohorts (GAPPS, CANDLE, TIDES). Women reported the duration of any and exclusive breastfeeding and child asthma outcomes during follow-up at child age 4 to 6 years. Outcomes included current wheeze (previous 12 months), ever asthma, current asthma (having ≥2 of current wheeze, ever asthma, medication use in past 12-24 months), and strict current asthma (ever asthma with either or both current wheeze and medication use in past 12-24 months). We used multivariable logistic regression to assess associations (odds ratios and 95% confidence intervals) between breastfeeding and asthma outcomes adjusting for potential confounders. We assessed effect modification by mode of delivery, infant sex, and maternal asthma.

RESULTS

Among women, 33%, 13%, 9%, and 45% reported 0 to less than 2, 2 to 4, 5 to 6, and more than 6 months of any breastfeeding, respectively. The duration of any breastfeeding had a protective linear trend with ever asthma but no other outcomes. There was a duration-dependent protective association of exclusive breastfeeding and child asthma outcomes (eg, current asthma adjusted odds ratio [95% confidence interval], 0.64 [0.41-1.02], 0.61 [0.38-0.98], and 0.52 (0.31-0.87) for 2to 4 months, 5 to 6 months, and more than 6 months, respectively, compared with <2 months). For exclusive breastfeeding, protective associations were stronger in dyads with children born by vaginal vs cesarean delivery although interactions did not reach statistical significance (Pinteractions 0.12-0.40).

CONCLUSION

Longer duration of exclusive breastfeeding had a protective association with child asthma.

Respiratory and allergic health effects in children living near agriculture: A review

BACKGROUND

Exposure to pesticides and agricultural burning are likely to co-occur in agricultural communities, but these exposures have remained distinct bodies of research. We reviewed epidemiological studies to identify the respiratory health effects of children exposed to pesticides and agricultural burning through a systematic evaluation of peer-reviewed publications of children living in industrial agricultural areas.

METHODS

Two academic search databases (PubMed and Scopus) were queried for all available studies published in English before May 31st, 2021. The initial search combining both exposure metrics (pesticides and agricultural burning) yielded zero publications and thus the queries were performed and presented separately.

RESULTS

Studies were categorized based on main exposure of interest (i.e., pesticides or agricultural burning) and by respiratory health outcome assessment (i.e., self-reported asthma, acute respiratory symptoms, and lung function measurements). In total we identified 25 studies that focused on pesticide exposures and children's respiratory health, and 12 studies that focused on exposure to agricultural burning and children's respiratory health. A majority of the pesticide studies (18/25) reported a positive association between exposure to pesticides and adverse childhood respiratory health effects. Similarly, most (11/12) of the agricultural burning studies also reported a positive association between exposure to agricultural burning and adverse respiratory health effects.

CONCLUSION

The most frequently studied health outcomes in these publications were acute respiratory symptoms (n = 11 pesticides, n = 3 agricultural burning), followed by asthma (n = 9 pesticides, n = 3 agricultural burning), and lung function measurements (n = 5 pesticides, n = 6 agricultural burning). Although health outcome assessment differed between pesticide studies and agricultural burning studies, similar adverse respiratory health effects were observed across the majority of studies.

Cord blood IgE predicts allergic sensitization, elevation of exhaled nitric oxide, and asthma in schoolchildren

BACKGROUND

Few data are available in Asian children regarding the validity of cord blood immunoglobulin E (IgE) in predicting allergic sensitization and pulmonary function. The relationship between cord blood IgE and fraction of exhaled nitric oxide (FeNO) remains unknown. This study investigated the associations of cord blood IgE with allergic sensitization, FeNO, pulmonary function, and allergic diseases in Asian children.

METHODS

Five hundred and sixty-six Asian children with valid cord blood IgE measurements at birth participated a 6-year follow-up visit including a questionnaire, serum total and allergen-specific IgE, FeNO measurement, and spirometry. Regression-based analyses with covariates adjustment were applied.

RESULTS

Cord blood IgE levels were significantly associated with FeNO levels (β = 0.131, p < .001) and serum total IgE levels (β = 0.325, p < .001). Cord blood IgE levels were positively associated with allergic sensitization (adjusted odds ratio [AOR] = 2.22, p < .001), and sensitization to mites (p = .002), animals (p = .023), and foods (p = .048). Subjects with cord blood IgE ≥0.24 kU/L (the optimal cutoff) were significantly associated with an increased risk of allergic sensitization (AOR = 2.63, p < .001) and asthma (AOR = 2.35, p = .024) than those with cord blood IgE <0.24 kU/L. Subjects with cord blood IgE ≥0.24 kU/L had significantly higher FeNO levels than those with cord blood IgE <0.24 kU/L (p = .028). There were no significant associations between cord blood IgE levels and pulmonary function parameters.

CONCLUSION

Cord blood IgE ≥0.24 kU/L predicts allergic sensitization, FeNO elevation, and asthma among Asian schoolchildren, suggesting cord blood IgE would be useful for identifying newborns at risk of subsequent allergic sensitization and allergic airway inflammation.

Cord blood sphingolipids are associated with atopic dermatitis and wheeze in the first year of life

Background

Allergen-sensitized pregnant mice have increased plasma levels of the lipids β-glucosylceramides (βGlcCers) that are transplacentally transferred to the fetus, increased subsets of proinflammatory dendritic cells in the fetal liver and pup lung, and increased allergen-induced offspring lung inflammation.

Objective

Our aim was to determine whether these preclinical observations extend to a human association of βGlcCers with wheeze and allergic disease in the prospective Wisconsin Infant Study Cohort.

Methods

We measured 74 lipids in cord blood plasma by using mass spectrometry detection of sphingolipids, eicosanoids, and docosinoids, as well as an ELISA for 13-hydroxyoctadecadienoic acid. Lipid profiles were determined by unbiased Uniform Manifold Approximation and Projection dimensional reduction machine learning. Lipid profiles and a proinflammatory lipid index were analyzed for association with maternal allergy and childhood outcomes of wheeze, atopic dermatitis, cord blood leukocytes, and total IgE level at age 1 year.

Results

Uniform Manifold Approximation and Projection analysis of lipids defined 8 cluster-specific plasma lipid profiles. Cluster 6 had significantly lower levels of plasma βGlcCers and a higher frequency of cord blood plasmacytoid dendritic cells that mediate anti-inflammatory responses, which is consistent with an anti-inflammatory profile. For clusters and for each infant, a proinflammatory lipid index was calculated to reflect the sum of the proinflammatory lipids minus the anti-inflammatory lipids that were significantly different than in cluster 6. The cluster proinflammatory lipid index was associated with cord blood basophil frequency and with wheeze and atopic dermatitis in the first year of life. The infant inflammatory lipid index was associated with increased risk of wheeze in the first year of life.

Conclusion

The cord blood proinflammatory lipid index is associated with early-life atopic dermatitis and wheezing.

Malocclusions in Pediatric Patients with Asthma: A Case-Control Study

Asthma is a public health problem that has been widely described, but little has been reported about its effects on dental occlusions. The aim of this study was to compare the alterations of normal occlusions in asthmatic children and those without the disease. The study included 186 patients between 5 and 12 years old, divided into two groups. The first group included patients with a previous diagnosis of asthma given by a specialist, which was confirmed by using the International Study of Asthma and Allergies in Childhood questionnaire. The second group included patients without the disease. All patients underwent a clinical examination to determine the presence of occlusion alterations in the sagittal, transverse, and vertical planes. Subsequently, chi-squared tests were performed to compare the variables between the groups. A significant association was found between asthma and the variables studied here: alterations in the sagittal plane (chi2 = 7.839, p = 0.005), alterations in the vertical plane (chi2 = 13.563, p < 0.001), alterations in the transverse plane (Fisher’s F p < 0.001), and oral habits (chi2 = 55.811, p < 0.001). The results suggest that asthmatic patients are more likely to develop malocclusions, especially anterior open bite and posterior crossbite. These conditions are typically related to mouth breathing, which is common in asthmatic patients.

Time-trends for eczema prevalences among children and adults from 1985 to 2015 in China: a systematic review

Background

Several studies have reported that childhood prevalence of eczema has been increasing worldwide. However, none study quantitatively evaluated prevalence trends of eczema among children and adults in the last 30 years in China.

Methods and Findings

Via a systematic review of literature databases in English and Chinese, we summarized all studies reporting eczema prevalences from 1985 to 2015 in China as well as diagramed prevalence and eczematous population trends against year for different age groups. A total of 93 studies and 17 studies (16 for children and one for adults) were selected for qualitative and quantitative synthesis, respectively. Childhood lifetime-ever eczema prevalences ranged from 10.0% to 30.0%. Prevalences among 3-12-year-olds children showed increasing trends in most specific cities, but national lifetime-ever eczema prevalences among 13-14-year-olds children decreased from 10.6% in 2001 to 8.6% in 2009 in mainland China. We estimated that about 1.5 million children aged 13-14-year-olds in 2009 and 15.5 million children aged 3-6-year-olds in 2012 had lifetime-ever eczema in mainland China. Similar studies were too few to ascertain time-trends of eczema prevalence among adults. About 39.4, 20.0, and 11.6 million adults aged 15-86-year-olds in 2010 had contact dermatitis, seborrheic dermatitis, and atopic dermatitis in the mainland China, respectively.

Conclusions

The burden of eczema became heavier in young children, whereas perhaps had been reduced in adolescent in China. More studies for eczema prevalence in adults are warranted.

The Family Impact of Atopic Dermatitis in the Pediatric Population: Results from an International Cross-sectional Study

OBJECTIVE

To evaluate the impact of atopic dermatitis on families of pediatric patients.

STUDY DESIGN

This cross-sectional, web-based survey of children/adolescents (6 months to <18 years old) with atopic dermatitis and their parents and caregivers was conducted in 18 countries encompassing North America, Latin America, Europe, Middle East/Eurasia, and East Asia. Children and adolescents with atopic dermatitis and their parents and caregivers were identified by the International Study of Asthma and Allergies in Childhood criteria and ever being told by a physician that they had "eczema". Atopic dermatitis severity was assessed using the Patient-Oriented Eczema Measure and the Patient Global Assessment. Atopic dermatitis impact on families' lives was evaluated using the Dermatitis Family Impact questionnaire and stand-alone questions on hours of atopic dermatitis-related care (past week) and missed work days (past 4 weeks) owing to their child's atopic dermatitis.

RESULTS

A total of 7465 pairs of pediatric participants with atopic dermatitis and their parents or caregivers were surveyed. Across age groups, the Dermatitis Family Impact questionnaire total score for all regions ranged from 7.1 to 8.6, 13.2 to 14.9, and 17.0 to 17.2 for Patient-Oriented Eczema Measure mild, moderate, and severe atopic dermatitis, respectively. Subscale scores showed that greater atopic dermatitis severity had a greater impact on all family life domains, including sleep and tiredness. No specific patterns or trends were observed across age groups. Time spent on childcare and missed work days increased with atopic dermatitis severity.

CONCLUSIONS

Across pediatric age groups and geographic regions, greater atopic dermatitis severity was associated with a greater negative impact on physical, emotional, social, and economic components of family life.

Asthma risk after a pediatric intensive care unit admission for respiratory syncytial virus bronchiolitis

BACKGROUND

Admission to a pediatric intensive care unit (PICU) has been associated with respiratory consequences in children with asthma and carries major implications for management control. Whereas respiratory syncytial virus (RSV) bronchiolitis has been associated with increasing intensity of wheezing, the relationship between RSV-bronchiolitis PICU admission and future asthma is unclear. This retrospective case-control study evaluated whether hospitalization in the PICU due to RSV bronchiolitis is more likely to be associated with future asthma in early life compared with hospitalization in a general pediatric ward.

METHODS

Children hospitalized due to RSV bronchiolitis between 2007 and 2019 in the PICU (study group) were compared to those hospitalized in a general pediatric ward (controls). Asthma prevalence was assessed by a follow-up questionnaire based on The International Study of Asthma and Allergies in Childhood questionnaire.

RESULTS

Sixty-three PICU patients and 66 controls were included. The PICU patients presented with more severe disease during RSV hospitalization. At follow-up, significantly more PICU patients aged 3-6 years had physician-diagnosed asthma, respiratory symptoms during the previous 12 months, and underwent respiratory treatment since hospital discharge compared to controls (14 [60.9%] vs. 4 [18.2%] patients; 15 [65.2%] vs. 6 [27.3%]; and 16 [69.6%] vs. 8 [36.4%]; respectively). These differences were no longer observed after 6 years of age.

CONCLUSIONS

Children admitted to the PICU for RSV bronchiolitis are at higher risk for asthma in subsequent pre-school years and will require close respiratory follow-up than those admitted to general pediatric wards. Admission venue should be queried when asthma is suspected.

Farm living and allergic rhinitis from childhood to young adulthood - prospective results of the GABRIEL study

BACKGROUND

Growing up on a farm is associated with a reduced prevalence of respiratory allergies in childhood. It is unknown whether this protective effect remains into adulthood.

OBJECTIVES

We aimed to prospectively investigate the relationship between farm exposure and prevalence of allergic rhinitis and wheeze from childhood to early adulthood.

METHODS

Participants from phase 2 of the GABRIEL (Multidisciplinary Study to Identify the Genetic and Environmental Causes of Asthma in the European Community) study living in southern Germany (aged 6-11 years at baseline; 20-25 at follow-up) were invited to complete a questionnaire on sociodemographic data, farm contact, respiratory symptoms, and potential confounders. Odds ratios (OR) with 95% confidence intervals (95% CI) were modelled using generalized estimating equations (GEE).

RESULTS

Of the 2,276 phase 2 participants, 1,501 (66%) answered the follow-up questionnaire of which 1,333 could be included in the analyses. Living on a farm was associated with reduced prevalence of allergic rhinitis (persistent farm living OR 0.4; 95% CI 0.2-0.6; only baseline farm living 0.4; 0.2-0.8). The odds ratio for developing symptoms from baseline to follow-up was almost three (OR 2.7; 95% CI 2.1-3.3), irrespective of farm living. For symptoms of wheeze, no statistically significant association with farm living was observed.

CONCLUSIONS

The protective effect of farm living on allergic rhinitis persists from childhood to early adulthood. Continuing exposure over puberty does not add to the effect. This confirms that the window of opportunity for a protective effect might be found in childhood.