Maternal smoking increases risk of allergic sensitization and wheezing only in children with allergic predisposition: longitudinal analysis from birth to 10 years

The impact of exposure to tobacco smoke and e-cigarettes on asthma-related outcomes: Systematic review informing the EAACI guidelines on environmental science for allergic diseases and asthma

To inform the clinical practice guidelines' recommendations developed by the European Academy of Allergy and Clinical Immunology systematic reviews (SR) assessed using GRADE on the impact of environmental tobacco smoke (ETS) and active smoking on the risk of new-onset asthma/recurrent wheezing (RW)/low lung function (LF), and on asthma-related outcomes. Only longitudinal studies were included, almost all on combustion cigarettes, only one assessing e-cigarettes and LF. According to the first SR (67 studies), prenatal ETS increases the risk of RW (moderate certainty evidence) and may increase the risk of new-onset asthma and of low LF (low certainty evidence). Postnatal ETS increases the risk of new-onset asthma and of RW (moderate certainty evidence) and may impact LF (low certainty evidence). Combined in utero and postnatal ETS may increase the risk of new-onset asthma (low certainty evidence) and increases the risk of RW (moderate certainty evidence). According to the second SR (24 studies), ETS increases the risk of severe asthma exacerbations and impairs asthma control and LF (moderate certainty evidence). According to the third SR (25 studies), active smoking increases the risk of severe asthma exacerbations and of suboptimal asthma control (moderate certainty evidence) and may impact asthma-related quality-of-life and LF (low certainty evidence).

Intra-Airway Treatment with Synthetic Lipoxin A4 and Resolvin E2 Mitigates Neonatal Asthma Triggered by Maternal Exposure to Environmental Particles

Particulate matter in the air exacerbates airway inflammation (AI) in asthma; moreover, prenatal exposure to concentrated urban air particles (CAPs) and diesel exhaust particles (DEPs) predisposes the offspring to asthma and worsens the resolution of AI in response to allergens. We previously tested the hypothesis that such exposure impairs the pathways of specialized proresolving mediators that are critical for resolution and found declined Lipoxin A4 (LxA4) and Resolvin E2 (RvE2) levels in the "at-risk" pups of exposed mothers. Here, we hypothesized that supplementation with synthetic LxA4 or RvE2 via the airway can ameliorate AI after allergen exposure, which has not been tested in models with environmental toxicant triggers. BALB/c newborns with an asthma predisposition resultant from prenatal exposure to CAPs and DEPs were treated once daily for 3 days with 750 ng/mouse of LxA4 or 300 ng/mouse of RvE2 through intranasal instillation, and they were tested with the intentionally low-dose ovalbumin protocol that elicits asthma in the offspring of particle-exposed mothers but not control mothers, mimicking the enigmatic maternal transmission of asthma seen in humans. LxA4 and RvE2 ameliorated the asthma phenotype and improved AI resolution, which was seen as declining airway eosinophilia, lung tissue infiltration, and proallergic cytokine levels.

Epigenetic/genetic variations in CG-rich elements of immune-related genes contribute to food allergy development during childhood

BACKGROUND

Genetic areas of FOXP3 TSDR, human leukocyte antigen-G (HLA-G) upstream of CpG island 96, CpG41 and CpG73 islands of the HLA-DRB1 and HLA-DQB1 genes respectively, previously documented to display immune-modulatory properties, were subjected to epigenetic/genetic analysis to assess their influence in IgE-mediated food allergy (FA) development in children.

METHODS

Sixty-four orally challenged and IgE-tested food allergic subjects together with 44 controls were recruited. Targeted pyrosequencing analysis to detect DNA methylation status and genetic variations was utilized and experimental results obtained were analyzed by a statistical software platform and correlated to clinical data. Also, transcription factor (TF) binding sites in study areas were unmasked by the JASPAR prediction database.

RESULTS

Parents' smoking was significantly correlated with aberrant methylation patterns, regardless of food allergic or control status. HLA-G promoter region showed a trend for hypomethylation in food allergic subjects, with one of the CG sites displaying significantly decreased methylation values. Rs1233333, residing within the HLA-G promoter region preserved a protective role toward DNA methylation. Variable methylation patterns were recorded for CpG41 of the HLA-DRB1 gene and hypermethylation of the region was significantly correlated with the presence of single nucleotide polymorphisms (SNPs). TFs' recognition sites, located in studied genetic areas and exerting pivotal regulatory biological roles, are potentially affected by divergent DNA methylation status.

CONCLUSIONS

We propose that HLA-G expression is triggered by food-derived allergens, providing a Treg^{FoxP3-/HLA-G+} subpopulation generation to promote direct immune tolerance. Furthermore, clear evidence is provided for the underlying co-operation of genetic polymorphisms with epigenetic events, mainly at the CpG41 island of the HLA-DRB1 gene, which needs an extended investigation and elucidation.

Prevalence and early-life risk factors of school-age allergic multimorbidity: The EuroPrevall-iFAAM birth cohort

Background

Coexistence of childhood asthma, eczema and allergic rhinitis is higher than can be expected by chance, suggesting a common mechanism. Data on allergic multimorbidity from a pan‐European, population‐based birth cohort study have been lacking. This study compares the prevalence and early‐life risk factors of these diseases in European primary school children.

Methods

In the prospective multicentre observational EuroPrevall‐iFAAM birth cohort study, we used standardized questionnaires on sociodemographics, medical history, parental allergies and lifestyle, and environmental exposures at birth, 12 and 24 months. At primary school age, parents answered ISAAC‐based questions on current asthma, rhinitis and eczema. Allergic multimorbidity was defined as the coexistence of at least two of these.

Results

From 10,563 children recruited at birth in 8 study centres, we included data from 5,572 children (mean age 8.2 years; 51.8% boys). Prevalence estimates were as follows: asthma, 8.1%; allergic rhinitis, 13.3%; and eczema, 12.0%. Allergic multimorbidity was seen in 7.0% of the whole cohort, ranging from 1.2% (Athens, Greece) to 10.9% (Madrid, Spain). Risk factors for allergic multimorbidity, identified with AICc, included family‐allergy‐score, odds ratio (OR) 1.50 (95% CI 1.32–1.70) per standard deviation; early‐life allergy symptoms, OR 2.72 (2.34–3.16) for each symptom; and caesarean birth, OR 1.35 (1.04–1.76). Female gender, OR 0.72 (0.58–0.90); older siblings, OR 0.79 (0.63–0.99); and day care, OR 0.81 (0.63–1.06) were protective factors.

Conclusion

Allergic multimorbidity should be regarded as an important chronic childhood disease in Europe. Some of the associated early‐life factors are modifiable and may be considered for prevention strategies.

"Effects of Tobacco Smoke on Aeroallergen Sensitization and Clinical Severity among University Students and Staff with Allergic Rhinitis"

Allergic diseases, affecting a variety of organs, have continuously increased both in developed and developing countries. Tobacco smoke exposure increases prevalence of allergic rhinitis (AR) and may affect allergic sensitization. This study was designed to compare indoor-aeroallergen sensitization between those not exposed and exposed to tobacco smoke in university students and staff with allergic rhinitis. A cross-sectional descriptive study among university students and staff with allergic rhinitis was performed from February 1, 2018, to March 31, 2019. Questionnaires regarding demography, clinical symptoms, and tobacco smoke exposure were implemented. A current smoker was defined as using, at least, 1 cigarette per day for, at least, 1 month. A secondhand smoker was defined as the one who never smoked, but lived with a current smoker, at least, for 1 month. A skin prick test for eight common indoor aeroallergens, Dermatophagoides pteronyssinus, Dermatophagoides farinae, Periplaneta americana, cat dander, dog dander, para grass, careless weed, and Cladosporium spp., was performed. Sensitization was defined as positivity to, at least, 1 aeroallergen. One hundred and twenty-eight adult patients were eligible participants for the study, and 68 cases (53.10%) were classified as having tobacco smoke exposure. Among these, most of them were secondhand smokers (50 cases, 73.50%). There was no statistically significant difference between exposure and nonexposure to tobacco smoke and indoor aeroallergen sensitization, except for the Periplaneta americana antigen (p=0.013). Most of those in the nonexposure group (34 cases, 56.70%) were classified as having intermittent allergic rhinitis, whereas the tobacco exposure group had significantly more prevalence of severe clinical symptoms. In conclusion, tobacco smoke exposure did not appear to have much influence on aeroallergen sensitization for 7 of the 8 antigens examined. However, for the Periplaneta americana antigen, there was a highly significant correlation with patients experiencing worsened allergic rhinitis symptoms. Overall, it was observed that allergic rhinitis patients exposed to tobacco smoke had more severe clinical symptoms. Future studies should look for other potential antigens of interest, such as mould. Implementation of public health practices reducing exposure to tobacco smoke could have benefits in allergic rhinitis patients.

Determinants of Allergic Sensitization, Asthma and Lung Function: Results from a Cross-Sectional Study in Italian Schoolchildren

Prenatal smoking exposure and early-life respiratory infections are major determinants of asthma during childhood. We investigate the factors influencing allergic sensitization (AS), asthma, and lung function in children and the balance between individual and environmental characteristics at different life stages. 1714 children aged 7–16 years and living in southern Italy were investigated using a parental questionnaire, skin prick tests, and spirometry. We found 41.0% AS prevalence: among children without parental history of asthma, male sex, maternal smoking during pregnancy (MatSmoke), and acute respiratory diseases in the first two years of life (ARD2Y) were significant risk factors for AS. MatSmoke was associated (OR = 1.79) with ARD2Y, and this association was influenced by sex. ARD2Y was, in turn, a significant risk factor (OR = 8.53) for childhood current asthma, along with AS (OR up to 3.03) and rhinoconjuctivitis (OR = 3.59). Forced mid-expiratory flow (FEF_25–75%) was negatively affected by ARD2Y, with a sex-related effect. Thus, males exposed to MatSmoke had significantly lower FEF_25–75% than unexposed males. Despite the difficulty of discriminating among the complex interactions underlying the development of allergic respiratory diseases, ARD2Y appears to strongly influence both asthma and lung function during childhood. In turn, ARD2Y is influenced by prenatal exposure to tobacco smoke with a sex-dependent effect.

Association of early daycare attendance with allergic disorders in children: a longitudinal national survey in Japan

The association between early daycare attendance and risk of allergic diseases remains inconclusive. Therefore, we examined the association among Japanese children on a long-term basis using a nationwide longitudinal survey data. We estimated the association between daycare attendance at age 6 or 18 months and allergy development using information on outpatient visits for atopic dermatitis (AD), food allergy (FA), and asthma and admission for asthma up to 12 years of age as a proxy for developing these diseases, with multilevel logistic regression. Early daycare attendance was associated with increased odds of AD at ages 2.5-3.5 years: the adjusted odds ratio (OR) was 1.34 [95% CI: 1.21, 1.47]. The association with FA was equivocal. The odds of asthma was increased before age 3.5 years and afterwards decreased: the adjusted ORs were 1.60 [1.44, 1.77] for ages 1.5-2.5 years and 0.77 [0.69, 0.87] for ages 5.5-7 years. The effect of early daycare attendance depends on the type of allergies.

Early Intervention is Important to Prevent Sensitization to New Allergens

We review current management for allergic rhinitis and possible new treatments for this condition. Management of allergic rhinitis includes promotion of protective factors, avoidance of allergens, and possibly immunotherapy. In recent years, the incidence of allergic rhinitis has increased in many countries. Early intervention at different stages is an important part of management. Allergic disease in infants has been described as the allergic march, commencing with atopic dermatitis accompanied by infantile asthma and progressing to perennial allergic rhinitis induced by house dust mite allergy. In order to prevent polysensitization, allergen-specific immunotherapy should probably be initiated at an earlier age, especially in children with rhinitis who show monosensitization to house dust mite antigens.

The current prevalence of asthma, allergic rhinitis, and eczema related symptoms in school-aged children in Costa Rica

OBJECTIVE

Asthma prevalence in Costa Rica is among the highest worldwide. We aimed to determine the prevalence of asthma among school-age children in the Central Highland Area of Costa Rica.

METHODS

Cross-sectional study using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was performed. Parents or guardians of children aged 6-13 years completed written questionnaires.

RESULTS

Total of 2817 school-aged children returned these questionnaires (74.1% return rate). The prevalence of asthma, rhinitis, and eczema was 21.9%, 42.6%, and 19.2%, respectively. The co-existence of the 3 diseases was seen in 22.6% of children with asthma. Boys had a slightly higher prevalence of these conditions, and younger children had higher prevalence of asthma and eczema, but lower prevalence of rhinitis than older children. The use of acetaminophen and antibiotics in the first 12 months of life showed a significant association with the prevalence of asthma, rhinitis, and eczema. Wheezing with exercise, dry cough at night, and ever rhinitis was highly associated with asthma symptoms in the last 12 months. In contrast, no association was found between children exposed to smoking at home. Frequent traffic next to the house was reported more frequently by the parents of children with asthma, although no significant association was found.

CONCLUSION

The prevalence of asthma showed a significant decrease compared to previous studies. However, there was an unexpected high prevalence of rhinitis. Exposure to acetaminophen and antibiotic during the first year of life was highly associated with asthma symptoms.

International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis

BACKGROUND

Critical examination of the quality and validity of available allergic rhinitis (AR) literature is necessary to improve understanding and to appropriately translate this knowledge to clinical care of the AR patient. To evaluate the existing AR literature, international multidisciplinary experts with an interest in AR have produced the International Consensus statement on Allergy and Rhinology: Allergic Rhinitis (ICAR:AR).

METHODS

Using previously described methodology, specific topics were developed relating to AR. Each topic was assigned a literature review, evidence-based review (EBR), or evidence-based review with recommendations (EBRR) format as dictated by available evidence and purpose within the ICAR:AR document. Following iterative reviews of each topic, the ICAR:AR document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:AR document addresses over 100 individual topics related to AR, including diagnosis, pathophysiology, epidemiology, disease burden, risk factors for the development of AR, allergy testing modalities, treatment, and other conditions/comorbidities associated with AR.

CONCLUSION

This critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding.

Exposure to tobacco smoke and childhood rhinitis: a population-based study

Exposure to tobacco smoke has been associated with harmful effects on child health. The association between tobacco smoke exposure and childhood rhinitis has not been established in developed or developing countries. We investigated the association between serum cotinine levels and rhinitis in a population sample of 1,315 Asian children. Serum cotinine levels were positively associated with rhinitis ever (adjusted odds ratio [AOR] = 2.95; 95% confidence interval [CI]: 1.15–7.60) and current rhinitis (AOR = 2.71; 95% CI: 1.07–6.89), while the association for physician-diagnosed rhinitis approaching borderline significance (AOR = 2.26; 95% CI: 0.88–5.83). Stratified analyses demonstrated significant association of serum cotinine levels with current rhinitis among children without allergic sensitization (AOR = 6.76; 95% CI: 1.21–37.74), but not among those with allergic sensitization. Serum cotinine levels were positively associated with rhinitis ever (AOR = 3.34; 95% CI: 1.05–10.61) and current rhinitis (AOR = 4.23; 95% CI: 1.28–13.97) among adolescents but not in children aged less than 10 years. This population-based study demonstrates supportive evidence for positive association of tobacco smoke exposure with rhinitis, while the effect is mainly confined to non-allergic rhinitis and more pronounced in adolescents than in young children, highlighting the need for raising public health awareness about the detrimental effects of tobacco smoke exposure on children’s respiratory health.

Effect of smoking status and nicotine dependence on pain intensity and outcome of treatment in Indian patients with temporomandibular disorders: A longitudinal cohort study

PURPOSE

Evidence regarding the association of smoking with various forms of chronic musculoskeletal pain is vast, but that with temporomandibular disorders (TMD) is scarce.

AIMS

The aims of this study are to evaluate the effect of smoking status (SS) and nicotine dependence (ND) on TMD pain intensity and treatment outcome in an Indian population with TMD.

SUBJECTS AND METHODS

Nine hundred and sixty-two patients with TMD were selected for this longitudinal cohort study. Lifetime SS was evaluated and patients were classified as current smokers (YS), former smokers (FS), or nonsmokers (NS). The Fagerstrom test was used to evaluate the ND of YS. Pain intensity was evaluated using visual analog scale scores. Six months posttreatment, the pain intensity was again recorded. The effect of treatment was evaluated using a global transition outcome measure and categorized as treatment success or failure. A minimum 30% reduction in pain was used as a criterion for categorizing patients as those who had gotten "better." Data obtained from the study were compared using Chi-square tests, paired samples t-tests, and one-way ANOVA tests. The criterion for statistical significance for all analyses was set at P = 0.05.

RESULTS

Among groups of SS, YS showed the maximum pain intensity at baseline and posttreatment. The outcome of treatment was most successful in NS and least in FS. The number of patients who had gotten "better" after treatment was significantly highest in NS. There was no significant difference between groups of ND with respect to pain intensity, treatment outcome, or "better" patients.

CONCLUSIONS

Among Indian patients with TMD, smokers reported significantly greater pain intensity and poorer response to treatment than NS. Pain intensity or treatment outcome was independent of ND.

The independent role of prenatal and postnatal exposure to active and passive smoking on the development of early wheeze in children

Maternal smoking during pregnancy increases childhood asthma risk, but health effects in children of nonsmoking mothers passively exposed to tobacco smoke during pregnancy are unclear. We examined the association of maternal passive smoking during pregnancy and wheeze in children aged ≤2 years.Individual data of 27 993 mother-child pairs from 15 European birth cohorts were combined in pooled analyses taking into consideration potential confounders.Children with maternal exposure to passive smoking during pregnancy and no other smoking exposure were more likely to develop wheeze up to the age of 2 years (OR 1.11, 95% CI 1.03-1.20) compared with unexposed children. Risk of wheeze was further increased by children's postnatal passive smoke exposure in addition to their mothers' passive exposure during pregnancy (OR 1.29, 95% CI 1.19-1.40) and highest in children with both sources of passive exposure and mothers who smoked actively during pregnancy (OR 1.73, 95% CI 1.59-1.88). Risk of wheeze associated with tobacco smoke exposure was higher in children with an allergic versus nonallergic family history.Maternal passive smoking exposure during pregnancy is an independent risk factor for wheeze in children up to the age of 2 years. Pregnant females should avoid active and passive exposure to tobacco smoke for the benefit of their children's health.

Prevalence of Allergic Rhinitis in Children in the Trabzon Province of the Black Sea Region of Turkey

Objective

We aimed to determine the prevalence of allergic rhinitis in children aged 12-15 years who lived in the Trabzon Province, specify possible risk factors, and compare the data obtained with those of the other studies conducted in our country and in other countries.

Methods

First, 1372 students from nine primary schools determined according to the recommendations of Department of Public Health and approval of The Provincial Directorate of Health were screened in their schools with questionnaire forms. Second, students providing the response "yes" to the first and/or second questions in the questionnaire forms were considered as possible allergic rhinitis patients and invited to our clinic. Then, 246 students were subjected to a skin prick test. Data were collected with the evalution of questionnaire and skin prick test results together.

Results

The prevalance of allergic rhinitis in children between 12 and 15 years age was found to be 14.5% in Trabzon. Female gender was found to be a relative a risk factor for allergic rhinitis (p=0.015). The prevalence of allergic rhinitis in children whose both parents were smoking was significantly higher than that in children whose only one parent was smoking or both parents were nonsmokers (p=0.0024). In addition, living in an apartment flat (p=0.015) and owing pets (p=0.04) were detected to be other risk factors for allergic rhinitis.

Conclusion

According to our investigations, this is the first prevalence study in Trabzon, which is the largest settlement in the Eastern Black Sea Region. The prevalence of allergic rhinitis in children was found to be 14.5%. Female gender, smoking habits of the parents, owing pets, and living in an apartment flat are risk factors for allergic rhinitis.

Parental smoking and development of allergic sensitization from birth to adolescence

Background

The relation between secondhand tobacco smoke (SHS) exposure and the development of allergic sensitization in children is unclear. The aim of this study was to determine whether maternal smoking during pregnancy and postnatal SHS exposure contributes to the development of allergic sensitization in children and adolescents up to 16 years of age.

Methods

We included 3316 children from a birth cohort followed up for 16 years. SHS exposure and symptoms of allergic disease were assessed using repeated parental questionnaires. Serum immunoglobulin E against eight common inhalant and six food allergens was assessed at ages 4, 8, and 16 years with ImmunoCAP. The association between SHS exposure and sensitization was explored using logistic regression and generalized estimating equations.

Results

Exposure to SHS in infancy without prior exposure in utero was associated with an excess risk of food sensitization at age 4 years (OR 1.47, 95% CI 1.08–2.00), with comparable ORs at ages 8 and 16 years. In longitudinal analyses, an overall association was indicated between SHS in infancy and food sensitization up to age 16 years (OR 1.24, 95% CI 0.98–1.56). Maternal smoking during pregnancy was unrelated to sensitization up to 16 years of age. When sensitization was combined with concurrent symptoms of allergic disease, SHS in infancy was associated with an overall elevated risk of eczema with sensitization (OR 1.62, 95% CI 1.20–2.18).

Conclusions

SHS exposure in infancy appears to increase the risk of sensitization to food allergens up to age 16 years, as well as eczema in combination with sensitization.

Tobacco smoke exposure and multiplexed immunoglobulin E sensitization in children: a population-based study

BACKGROUND

Although there is evidence that exposure to tobacco smoke is harmful to children's respiratory health, the effects of tobacco smoke exposure on the regulation of immunoglobulin E (IgE)-mediated immune responses to specific allergens remain unclear. This study aimed to investigate the relationship between objectively assessed tobacco smoke exposure and specific IgE profiles for a broad spectrum of allergens in a population setting.

METHODS

Children aged 5-18 years (N = 1315) were assessed using serum cotinine measurement and microarray-based multiplexed detection of specific IgE against 40 allergens.

RESULTS

Serum cotinine levels were positively associated with sensitization to foods (adjusted odds ratio [AOR] = 4.95; 95% CI: 1.59-15.34), cockroaches (AOR = 3.77; 95% CI: 1.49-9.51), and pollen (AOR = 2.84; 95% CI: 1.20-6.73) while the association was borderline significant for animals (AOR = 2.53; 95% CI: 0.92-6.93). No associations were found for sensitization against mites, mold, and latex. When considering the degree of allergic sensitization, serum cotinine levels were positively correlated to the number of sensitization to cockroaches (P = 0.004), pollen (P = 0.006), and foods (P < 0.001), with statistically significant positive dose-response relationships (all P < 0.01). Similar results were observed when summing up specific IgE concentrations for the aforementioned allergen categories.

CONCLUSIONS

The association between tobacco smoke exposure and IgE sensitization to environmental allergens varies for different allergens among children. This study demonstrates that elevated serum cotinine levels are significantly associated with IgE sensitization to cockroaches, grass pollen, and certain foods, with potential dose-dependent relationships.

Patterns of Sensitization to Inhalant Allergens in Japanese Lower-Grade Schoolchildren and Related Factors

OBJECTIVE

This study clarified sensitization patterns to house dust mite (HDM) and Japanese cedar pollen (JCP) in Japanese lower-grade schoolchildren. We also explored factors associated with allergic sensitization.

METHODS

This cross-sectional study used a database from the Study on Respiratory Disease and Automobile Exhaust (SORA), a Japanese health study project. The subjects comprised 8,815 pupils aged 6-9 years. We obtained the distribution of HDM- and JCP-specific IgE, respectively, as a marker of sensitization. To determine factors associated with sensitization, we used logistic regression and calculated adjusted odds ratios (AORs) for the relative prevalence of sensitization. The cut-off point for specific IgE levels was 0.35 kU/l.

RESULTS

Sensitization to HDM and JCP was detected in 51 and 39% of subjects, respectively, occurring more often in boys and at older ages. In addition, AORs of sensitization to HDM/JCP were higher in subjects with a history of bronchitis, parental asthma, parental atopic eczema and parental pollinosis. In contrast, AORs for sensitization were lower in those subjected to maternal passive smoking as well as among boys with pets. AORs of sensitization to JCP alone were lower in those with a history of otitis media, those who had been bottle milk fed, and those who were not the firstborn and who lived near a busy road.

CONCLUSION

Sensitization to HDM and JCP was detected in 51 and 39% of lower-grade schoolchildren, respectively.

Evaluation of in utero sensitization by screening antigen-specific immunoglobulin E levels in umbilical cord blood

INTRODUCTION

The incidence of asthma and atopic reactions is increasing worldwide. Previous reports have suggested that maternal exposure to allergens during pregnancy may have potential effects on allergic sensitization in infants.

AIM

To evaluate the effects of maternal exposure to environmental allergens during pregnancy on in-utero sensitization.

MATERIAL AND METHODS

Two hundred mothers and their infants were analyzed in this cross-sectional study. Mothers were given a questionnaire that had a series of questions to evaluate the maternal allergic status and environmental exposures during pregnancy. Plasma specific immunoglobulin E (IgE) levels to pets, grass, food (nuts) of all mothers and their infants were analyzed by an immune-enzymatic assay.

RESULTS

There was no significant correlation between plasma specific IgE positivity in mothers, with regard to keeping indoor domestic pets, living in grass habitat, eating nuts in diet. A significant correlation was found between specific IgE presence in mothers and allergic reactions; however, there was no correlation between plasma specific IgE positivity of mothers and infants.

CONCLUSIONS

We concluded that prenatal maternal sensitivity to environmental allergens could not be evaluated as a predictive factor for in-utero sensitization.

FLG P478S polymorphisms and environmental risk factors for the atopic march in Taiwanese children: a prospective cohort study

BACKGROUND

Little is known about the role of genetic and environmental modifiers in atopic march.

OBJECTIVE

To investigate the effects of filaggrin (FLG) P478S polymorphisms and environmental factors on the risk of asthma in a cohort of children with atopic dermatitis (AD).

METHODS

In 2010, 3,246 children from Childhood Environment and Allergic Diseases Cohort Study cohort were recruited. There were 485 children with AD who were invited for further clinical evaluation. Environmental exposures and skin prick tests for allergens were collected at 3 years of age and the development of asthma was determined at 6 years. Multivariate logistic regressions were performed to estimate the association between genetic and environmental factors and the development asthma in children with AD.

RESULTS

Of 397 children with AD who completed the follow-up, 97 developed asthma. After controlling for potential confounders, only mite sensitizations (odds ratio 1.89, 95% confidence interval 1.10-3.25) and the FLG TT genotype (odds ratio 2.26, 95% confidence interval 1.33-3.84) were significantly associated with the development of asthma in children with AD. Mite sensitizations and FLG variants had a synergistic effect on the development of asthma. When children with FLG variants were exposed to mite, the risk for asthma was compounded compared with those with FLG variants without mite exposure (odds ratio 3.58, 95% confidence interval 1.81-7.08).

CONCLUSION

Mite sensitization and the FLG TT genotype couldt be associated with the development of atopic march.

The role of the early-life environment in the development of allergic disease

A consensus has been reached that the development of allergic disorders is strongly influenced by early life exposures. An overview of several prenatal and early life factors that have been investigated for their associations with development of childhood allergy is presented. Delivery mode, the gut microbiome, vitamin D, folate, breastfeeding, pets, antibiotics, environmental tobacco smoke, and airborne traffic pollutants are discussed. Although many studies suggest an effect, overall, no risk factors clearly increase or reduce the risk of allergic outcomes.

Epigenomics and allergic disease

Allergic disease development is affected by both genes and the environment, and epigenetic mechanisms are hypothesized to mediate these environmental effects. In this article, we discuss the link between the environment, DNA methylation and allergic disease, as well as questions of causality inherent to analyses of DNA methylation. From the practical side, we describe characteristics of allergic phenotypes and contrast different epidemiologic study designs used in epigenetic research. We examine methodological considerations, how best to conduct preprocessing and analysis of DNA methylation data sets, and the latest methods, technologies and discoveries in this rapidly advancing field. DNA methylation and other epigenetic marks are firmly entwined with allergic disease, a link that may hold the basis for future allergic disease diagnosis and treatment.

A Multiple Indicators Multiple Cause (MIMIC) model of respiratory health and household factors in Chinese children: the seven Northeastern cities (SNEC) study

In China, with the rapid economic development and improvement of living standards over the past few decades, the household living environment has shifted dramatically. The aim of the present study is to assess the impact of home environment factors on respiratory symptoms and asthma in Chinese children. Investigators analyzed data collected in the 25 districts from the seven Northeastern cities to examine health effects on respiratory symptoms and asthma in 31,049 children aged 2-14 years. Factor analysis was used to reduce 33 children's lifestyle and household variables to six new 'factor' variables. The multiple indicators multiple causes approach was used to examine the relationship between indoor air pollution and respiratory health status, controlling for covariates. Factor analyses generated six factor variables of potential household risk factors from an original list of 33 variables. The respiratory symptoms and asthma were significantly associated with the recent home renovation factor (estimate = 0.076, p < 0.001), pet ownership factor (estimate = 0.095, p < 0.001), environmental tobacco smoke (ETS) exposure factor (estimate = 0.181, p < 0.001) and PVC-flooring factor (estimate = 0.031, p = 0.007). Home ventilation factor was not related to any respiratory condition (estimate = 0.028, p = 0.074). Independent respiratory health effects existed for multiple household environmental factors recent home renovation, pet ownership, ETS, and PVC-flooring.

Prevention of asthma: where are we in the 21st century?

Asthma is the most common chronic disease of childhood and, in the latter part of the 20th century, reached epidemic proportions. Asthma is generally believed to result from gene-environment interactions. There is consensus that a 'window of opportunity' exists during pregnancy and early in life when environmental factors may influence its development. We review multiple environmental, biologic and sociologic factors that may be important in the development of asthma. Meta-analyses of studies have demonstrated that multifaceted interventions are required in order to develop asthma prevention. Multifaceted allergen reduction studies have shown clinical benefits. Asthma represents a dysfunctional interaction with our genes and the environment to which they are exposed, especially in fetal and early infant life. The increasing prevalence of asthma also may be an indication of increased population risk for the development of other chronic non-communicable autoimmune diseases. This review will focus on the factors which may be important in the primary prevention of asthma. Better understanding of the complex gene-environment interactions involved in the development of asthma will provide insight into personalized interventions for asthma prevention.

The impact of tobacco smoke exposure on wheezing and overweight in 4-6-year-old children

Aim. To investigate the association between maternal smoking during pregnancy, second-hand tobacco smoke (STS) exposure, education level, and preschool children's wheezing and overweight. Methods. This cohort study used data of the KANC cohort—1,489 4–6-year-old children from Kaunas city, Lithuania. Multivariate logistic regression was employed to study the influence of prenatal and postnatal STS exposure on the prevalence of wheezing and overweight, controlling for potential confounders. Results. Children exposed to maternal smoking during pregnancy had a slightly increased prevalence of wheezing and overweight. Postnatal exposure to STS was associated with a statistically significantly increased risk of wheezing and overweight in children born to mothers with lower education levels (OR 2.12; 95% CI 1.04–4.35 and 3.57; 95% CI 1.76–7.21, accordingly). Conclusions. The present study findings suggest that both maternal smoking during pregnancy and STS increase the risk of childhood wheezing and overweight, whereas lower maternal education might have a synergetic effect. Targeted interventions must to take this into account and address household smoking.

The independent and combined effects of lifetime smoke exposures and asthma as they relate to COPD

Chronic obstructive pulmonary disease (COPD) is part of a worldwide tobacco-related disease epidemic, and is associated with progressive airflow obstruction and varying degrees of emphysema and/or hyperinflation. Greater focus has been placed recently on the potential for early life factors to influence the development of COPD, based on the premise that delayed lung growth during childhood and adolescence might predispose to lung disease in later life. For most people, the adverse effects on lung function of adult and early childhood factors are additive, which provides no additional incentive for current smokers to quit. However, if there is a (synergistic) interaction between active smoking and asthma, smoking cessation is likely to have a greater lung function benefit for the smoker who is also asthmatic, especially if quitting occurs at an early age. This article critically evaluates the evidence for the independent associations of lifetime asthma, smoking and smoke exposures with airflow obstruction, plus their interaction when multiple factors are present.

Trends in the prevalence of asthma

The asthma epidemic of the last few decades may have peaked; studies suggest that the incidence and prevalence of asthma has decreased in some countries in the last few years, although other studies suggest continuing small increases in prevalence. Increasing awareness and changing diagnostic habits make precise evaluation of epidemiologic trends difficult in the absence of a gold-standard test for asthma, and on a global basis uncertainty persists. Trends in prevalence in some populations (eg, immigrants, farming communities) suggest both adverse and beneficial effects of specific environmental factors. Although the effects of indoor allergens, dampness, and mold and of outdoor air pollutants, especially traffic related, have traditionally dominated risk-factor research, more recent epidemiologic and clinical studies have focused on metabolic and nutritional factors, including maternal obesity and vitamin D levels, mode of delivery and its effect on the infant microbiome, fetal and infant growth, the psychosocial environment, and medication use by mother and infant. It is likely that changes in incidence and prevalence are due to multiple factors, each contributing a relatively small effect. Longitudinal studies from pregnancy through childhood to adulthood will yield greater insights into the complex pathways leading to asthma.

Persistent effects of maternal smoking during pregnancy on lung function and asthma in adolescents

RATIONALE

The extent to which maternal smoking in pregnancy (MSP) has persisting effects on respiratory health remains uncertain and the mechanisms involved are not fully understood. Alterations in immune function have been proposed as a mechanism contributing to respiratory disease.

OBJECTIVES

To determine whether MSP increases risk of respiratory disorders in adolescence and, if so, whether this occurs by decreased lung function, altered immune function, and/or enhanced atopy.

METHODS

Data on spirometry, bronchial responsiveness, respiratory symptoms, total and allergen-specific IgE and IgG4, immune function, and inflammatory markers were obtained from 1,129 participants in the 14-year follow-up of the Western Australian Pregnancy (Raine) Cohort and related to MSP using regression analyses.

MEASUREMENTS AND MAIN RESULTS

MSP was reported for 21.0% (237 of 1,129) of participants, with 92 (8.1%) reporting current smoking. MSP was associated with some altered immune measures at age 14. MSP was strongly related to reduced lung function in current nonsmokers (forced expiratory flow midexpiratory phase [FEF25-75%], P = 0.016; FEV1/FVC, P = 0.009) and increased risk for current asthma (odds ratio [OR], 1.84; 95% confidence interval [CI], 1.16-2.92; P = 0.01), current wheeze (OR, 1.77; 95% CI, 1.14-2.75; P = 0.011), and exercise-induced wheeze (OR, 2.29; 95% CI, 1.37-3.85; P = 0.002), but not for bronchial hyperresponsiveness or atopy. Adjustment for immune measures and/or lung function in multivariate models did not greatly alter these associations and the increased risks for asthma and wheeze were not modified by sex, atopy, or maternal history of asthma or atopy.

CONCLUSIONS

MSP increases risk of asthma and wheezing in adolescence; mechanisms go beyond reducing lung function and exclude altering immune function or enhancing atopy.

Active or passive exposure to tobacco smoking and allergic rhinitis, allergic dermatitis, and food allergy in adults and children: a systematic review and meta-analysis

BACKGROUND

Allergic rhinitis, allergic dermatitis, and food allergy are extremely common diseases, especially among children, and are frequently associated to each other and to asthma. Smoking is a potential risk factor for these conditions, but so far, results from individual studies have been conflicting. The objective of this study was to examine the evidence for an association between active smoking (AS) or passive exposure to secondhand smoke and allergic conditions.

METHODS AND FINDINGS

We retrieved studies published in any language up to June 30th, 2013 by systematically searching Medline, Embase, the five regional bibliographic databases of the World Health Organization, and ISI-Proceedings databases, by manually examining the references of the original articles and reviews retrieved, and by establishing personal contact with clinical researchers. We included cohort, case-control, and cross-sectional studies reporting odds ratio (OR) or relative risk (RR) estimates and confidence intervals of smoking and allergic conditions, first among the general population and then among children. We retrieved 97 studies on allergic rhinitis, 91 on allergic dermatitis, and eight on food allergy published in 139 different articles. When all studies were analyzed together (showing random effects model results and pooled ORs expressed as RR), allergic rhinitis was not associated with active smoking (pooled RR, 1.02 [95% CI 0.92-1.15]), but was associated with passive smoking (pooled RR 1.10 [95% CI 1.06-1.15]). Allergic dermatitis was associated with both active (pooled RR, 1.21 [95% CI 1.14-1.29]) and passive smoking (pooled RR, 1.07 [95% CI 1.03-1.12]). In children and adolescent, allergic rhinitis was associated with active (pooled RR, 1.40 (95% CI 1.24-1.59) and passive smoking (pooled RR, 1.09 [95% CI 1.04-1.14]). Allergic dermatitis was associated with active (pooled RR, 1.36 [95% CI 1.17-1.46]) and passive smoking (pooled RR, 1.06 [95% CI 1.01-1.11]). Food allergy was associated with SHS (1.43 [1.12-1.83]) when cohort studies only were examined, but not when all studies were combined. The findings are limited by the potential for confounding and bias given that most of the individual studies used a cross-sectional design. Furthermore, the studies showed a high degree of heterogeneity and the exposure and outcome measures were assessed by self-report, which may increase the potential for misclassification.

CONCLUSIONS

We observed very modest associations between smoking and some allergic diseases among adults. Among children and adolescents, both active and passive exposure to SHS were associated with a modest increased risk for allergic diseases, and passive smoking was associated with an increased risk for food allergy. Additional studies with detailed measurement of exposure and better case definition are needed to further explore the role of smoking in allergic diseases.

Prevalence, severity and risk factors of asthma, rhinitis and eczema in a large group of Chinese schoolchildren

BACKGROUND

There is a lack of information on the prevalence, severity and risk factors of asthma, rhinitis and eczema in Chinese children.

OBJECTIVE

To establish baseline data for a major longitudinal study of factors affecting asthma, rhinitis and eczema in a large group of children from the industrialized city of Shijiazhuang, China.

METHODS

We used the International Study of Asthma and Allergies in Childhood questionnaire and studied 10 338 children, ages 6-18, from Shijiazhuang.

RESULTS

The prevalence of childhood asthma, rhinitis and eczema is 1.2%, 13.5% and 11.8%, respectively. Boys had higher prevalence of these conditions than girls and younger children had higher prevalence of asthma and eczema but lower prevalence of rhinitis than older children. Breastfed children had lower prevalence of asthma and rhinitis, but not eczema, than non-breastfed children. Overweight children had higher prevalence of asthma and rhinitis than those who were not overweight. Children exposed to paternal smoking had higher prevalence of rhinitis and eczema than those not exposed; children exposed to pets had higher prevalence of asthma and rhinitis than those not exposed.

CONCLUSIONS

The prevalence of asthma in this study group is low, but the prevalence of rhinitis is high, and could be considered a major public health problem. The prevalence of asthma, rhinitis and eczema is generally higher in boys and younger children generally have higher prevalence of asthma and eczema but lower prevalence of rhinitis. Exposure to pets is a risk factor for rhinitis, being overweight is a risk factor for asthma and rhinitis, and exposure to parental smoking is a risk factor for asthma, rhinitis and eczema in these children.

The natural course of allergic rhinitis: a 32-year follow-up study

CONCLUSION

Early intervention may change the natural course of allergic rhinitis, preventing the progression to asthma. In particular, immunotherapy guarantees remission of local symptoms and valid protection against local and bronchial complications. Symptomatic treatment represents a valid alternative; it is always to be preferred to abstention from any treatment.

OBJECTIVES

Data emerging from various studies on the increase of the prevalence of allergic rhinitis in recent decades appear to be widely dishomogeneous. Another point that needs clarification is the relationship between allergic rhinitis and lower airways pathologies such as asthma or bronchitis.

METHODS

We followed the evolution of allergic rhinitis in a group of patients for the last 30 years to highlight the efficacy of different treatments in the prevention of complications, specifically asthma. After 32 years (1980-2012), 46/73 (63%) patients completed the follow-up.

RESULTS

Symptomatic drugs exhibited maximum efficacy from the third to the eighth year, with 13 of 15 patients reporting an improvement of symptoms; immunotherapy achieved the best efficacy starting from the sixth to the tenth year (8 of 10 patients recovered). Subsequently, improvements decreased in the two groups, to a steady level of 11 of 15 and 6 of 10 recovered patients. Asthma developed in 3 of 46 patients and only among patients that were not treated.

Prenatal smoke exposure, DNA methylation, and childhood atopic dermatitis

BACKGROUND

The biological mechanisms of how prenatal smoke exposure leading to atopic disorders remain to be addressed. Whether prenatal smoke exposure affects DNA methylation leading to atopic disorders is not clear.

OBJECTIVE

As most children suffering from atopic dermatitis (AD) continue to develop asthma later in life, we explored whether prenatal smoke exposure induces cord blood DNA methylation.

METHODS

Methylation differences associated with smoke exposure were screened by Illumina Infinium 27K methylation arrays for 14 children from the Taiwan birth panel study cohort initially. Information about development of atopic dermatitis (AD) and risk factors was collected. Cord blood cotinine levels were measured to represent prenatal smoke exposure. CpG loci that demonstrated a statistically significant difference in methylation were validated by methylation-dependent fragment separation (MDFS). Differential methylation in three genes (TSLP, GSTT1, and CYB5R3) was identified through the screen.

RESULTS

Among these, only thymic stromal lymphopoietin (TSLP) gene displayed significant difference in promoter methylation percentage after being validated by MDFS (p = 0.018). TSLP gene was further investigated in a larger sample of 150 children from the cohort who completed the follow-up study. Methylation status of the TSLP 5'-CpG island (CGI) was found to be significantly associated with prenatal smoke exposure (OR = 3.17, 95% CI = 1.63-6.19) and with AD (OR = 2.32, 95% CI = 1.06-5.11). The degree of TSLP 5'CGI methylation inversely correlated with TSLP protein expression levels (r = -0.45, P = 0.001).

CONCLUSIONS & CLINICAL RELEVANCE

The effect of prenatal tobacco smoke exposure on the risk for AD may be mediated through DNA methylation.

What is new in the prevention of atopy and asthma?

PURPOSE OF REVIEW

Increasing understanding of mechanisms and influencing factors in the development of uncontrolled inflammatory responses in atopy and asthma should serve for the introduction of new preventive measures. This review tries to present the current state of the art and resumes that until now, no really effective concept can be offered to families at risk.

RECENT FINDINGS

In addition to modified feeding regimes (hydrolysed formula feeding in infancy), timing of the introduction of solids (avoidance of allergens versus early induction of tolerance), immune modulation using prebiotics or probiotics, a new target of potential intervention could be the human microbiome as a key player in the development of inflammatory diseases such as allergy and asthma. However, during the last 5 years, this concept could not yet be verified in interventional trials. There are new trials ongoing, studying the effect of microbial compounds in early infancy, vitamin D and polyunsaturated fatty acid supplementation during late pregnancy and the effect of azithromycin in children with recurrent wheeze. Results are to be expected within the next couple of years.

SUMMARY

New data on multifaceted intervention and the analysis of the human microbiome are to be expected. The recommendation for atopy and asthma prevention still focuses on avoidance of tobacco smoke exposure and food allergens during the first 4 months of life and feeding of hydrolysed formula if breast-feeding is not possible in high-risk infants, potentially early feeding of prebiotic sugars and/or certain strains of probiotic bacteria or bacterial compounds in certain subpopulations.

A motivational interviewing intervention to PREvent PAssive Smoke Exposure (PREPASE) in children with a high risk of asthma: design of a randomised controlled trial

Background

Especially children at risk for asthma are sensitive to the detrimental health effects of passive smoke (PS) exposure, like respiratory complaints and allergic sensitisation. Therefore, effective prevention of PS exposure in this group of vulnerable children is important. Based on previous studies, we hypothesized that an effective intervention program to prevent PS exposure in children is possible by means of a motivational interviewing tailored program with repeated contacts focussing on awareness, knowledge, beliefs (pros/cons), perceived barriers and needs of parents, in combination with feedback about urine cotinine levels of the children. The aim of the PREPASE study is to test the effectiveness of such an intervention program towards eliminating or reducing of PS exposure in children at risk for asthma. This article describes the protocol of the PREPASE study.

Methods

The study is a one-year follow-up randomized controlled trial. Families with children (0–13 years of age) having an asthma predisposition who experience PS exposure at home are randomized into an intervention group receiving an intervention or a control group receiving care as usual. The intervention is given by trained research assistants. The intervention starts one month after a baseline measurement and takes place once per month for an hour during six home based counselling sessions. The primary outcome measure is the percentage of families curtailing PS exposure in children (parental report verified with the urine cotinine concentrations of the children) after 6 months. The secondary outcome measures include: household nicotine level, the child’s lung function, airway inflammation and oxidative stress, presence of wheezing and questionnaires on respiratory symptoms, and quality of life. A process evaluation is included. Most of the measurements take place every 3 months (baseline and after 3, 6, 9 and 12 months of study).

Conclusion

The PREPASE study incorporates successful elements of previous interventions and may therefore be very promising. If proven effective, the intervention will benefit the health of children at risk for asthma and may also create opportunity to be tested in other population.

Trial registration number

NTR2632

Tobacco smoke exposure and allergic sensitization in children: a propensity score analysis

BACKGROUND AND OBJECTIVE

There is conflicting evidence of the effect of environmental tobacco smoke (ETS) on the development of allergic diseases in children. Studies have shown that this relationship differs depending on maternal history of the disease. We employed the rigour of propensity score methods to assess this relationship using data from a birth cohort.

METHODS

Using n = 662 children from the Wayne County Health, Environment, Allergy and Asthma Longitudinal Study, we assessed the relationship between early-life ETS and subsequent allergic sensitization via a positive skin prick test (SPT+) or at least one specific immunoglobulin E (IgE) ≥ 0.35 (sIgE+) in children aged 2-3 years. Propensity score estimation followed by full and nearest neighbour matching was compared with standard multivariable regression models.

RESULTS

Among children without a maternal history of allergic disease, ETS was positively associated with allergic sensitization in children with an adjusted odds ratio (aOR) for SPT+ of 2.32 (95% confidence interval (CI): 1.28-4.22) and the aOR for sIgE+ was 2.53 (95% CI: 1.43-4.48). Contrarily, for children with a positive maternal history, the aOR for SPT+ and sIgE+ was 0.56 (95% CI: 0.24-1.32) and 0.43 (95% CI: 0.20-0.91), respectively.

CONCLUSIONS

Using propensity score methods to rigorously control for confounding factors, ETS exposure was found to reduce the risk of allergic sensitization in children with a positive maternal history. There is a strong association between early-life ETS and the development of allergic sensitization for children aged 2-3 years without maternal history.

Early life precursors, epigenetics, and the development of food allergy

Food allergy (FA), a major clinical and public health concern worldwide, is caused by a complex interplay of environmental exposures, genetic variants, gene-environment interactions, and epigenetic alterations. This review summarizes recent advances surrounding these key factors, with a particular focus on the potential role of epigenetics in the development of FA. Epidemiologic studies have reported a number of nongenetic factors that may influence the risk of FA, such as timing of food introduction and feeding pattern, diet/nutrition, exposure to environmental tobacco smoking, prematurity and low birth weight, microbial exposure, and race/ethnicity. Current studies on the genetics of FA are mainly conducted using candidate gene approaches, which have linked more than 10 genes to the genetic susceptibility of FA. Studies on gene-environment interactions of FA are very limited. Epigenetic alteration has been proposed as one of the mechanisms to mediate the influence of early life environmental exposures and gene-environment interactions on the development of diseases later in life. The role of epigenetics in the regulation of the immune system and the epigenetic effects of some FA-associated environmental exposures are discussed in this review. There is a particular lack of large-scale prospective birth cohort studies that simultaneously assess the interrelationships of early life exposures, genetic susceptibility, epigenomic alterations, and the development of FA. The identification of these key factors and their independent and joint contributions to FA will allow us to gain important insight into the biological mechanisms by which environmental exposures and genetic susceptibility affect the risk of FA and will provide essential information to develop more effective new paradigms in the diagnosis, prevention, and management of FA.

Oral application of bacterial lysate in infancy decreases the risk of atopic dermatitis in children with 1 atopic parent in a randomized, placebo-controlled trial

BACKGROUND

Lower prevalence of atopy was found in children with continuous exposure to livestock and thus to microbial compounds. In animal models exposure to endotoxin (LPS) decreases allergic sensitization and airway inflammation.

OBJECTIVE

We sought to evaluate the effect of orally applied bacterial lysate in infancy on the prevalence of atopic dermatitis (AD) after the treatment phase at 7 months of age.

METHODS

This randomized, placebo-controlled trial included 606 newborns with at least single heredity for atopy. From week 5 until the end of month 7, infants were treated orally with bacterial lysate containing heat-killed gram-negative Escherichia coli Symbio and gram-positive Enterococcus faecalis Symbio or its placebo. Children were followed until 3 years of age.

RESULTS

There was no difference in the primary outcome between the active and placebo groups in the total study group. AD prevalence was significantly reduced at the end of the intervention phase (31 weeks of age) in the subgroup of infants with single heredity for atopy (relative risk, 0.52; 95% CI, 0.3-0.9). Ten percent (15/154) of infants in the active group had AD compared with 19% (27/145, P = .030) in the placebo group. This was more pronounced in the group of infants with paternal heredity for atopy (11% vs 32%, P = .004; relative risk, 0.34; 95% CI, 0.2-0.7).

CONCLUSION

Feeding of bacterial lysate might have prevented the development of AD, especially in children with paternal atopy, possibly indicating a preventive property only in subjects with a limited risk for atopy.

Prenatal and passive smoke exposure and incidence of asthma and wheeze: systematic review and meta-analysis

OBJECTIVES

Exposure to passive smoke is a common and avoidable risk factor for wheeze and asthma in children. Substantial growth in the prospective cohort study evidence base provides an opportunity to generate new and more detailed estimates of the magnitude of the effect. A systematic review and meta-analysis was conducted to provide estimates of the prospective effect of smoking by parents or household members on the risk of wheeze and asthma at different stages of childhood.

METHODS

We systematically searched Medline, Embase, and conference abstracts to identify cohort studies of the incidence of asthma or wheeze in relation to exposure to prenatal or postnatal maternal, paternal, or household smoking in subjects aged up to 18 years old. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were estimated by using random effects model.

RESULTS

We identified 79 prospective studies. Exposure to pre- or postnatal passive smoke exposure was associated with a 30% to 70% increased risk of incident wheezing (strongest effect from postnatal maternal smoking on wheeze in children aged ≤2 years, OR = 1.70, 95% CI = 1.24-2.35, 4 studies) and a 21% to 85% increase in incident asthma (strongest effect from prenatal maternal smoking on asthma in children aged ≤2 years, OR = 1.85, 95% CI = 1.35-2.53, 5 studies).

CONCLUSIONS

Building upon previous findings, exposure to passive smoking increases the incidence of wheeze and asthma in children and young people by at least 20%. Preventing parental smoking is crucially important to the prevention of asthma.

Validating childhood symptoms with physician-diagnosed allergic rhinitis

BACKGROUND

Multiple population-based and high-risk cohort studies use parental questionnaire responses to define allergic rhinitis (AR) in children. Individual questionnaire items have not been validated by comparison with physician-diagnosed AR (PDAR).

OBJECTIVE

To identify routine clinical questions that best agree with a physician diagnosis of AR and can be used for early case identification.

METHODS

Children participating in a longitudinal birth cohort study were evaluated at ages 1 through 4 and at age 7 (n = 531) using questionnaires, physical examinations, and skin prick tests (SPT) with 15 aeroallergens (AG). Parents answered 3 stem questions pertaining to their child, including presence of nasal symptoms absent a cold/flu (ISAAC-validated question), presence of hayfever, and ocular itch. Substem questions were answered with details regarding seasonality, nasal triggers, and ocular seasonality. A global assessment of allergic diseases, including AR, was performed by a specialty-trained clinician. Percent agreement, sensitivity, specificity, and positive predictive values were assessed for individual stem and substem questions.

RESULTS

Positive response to having hayfever and presence of ocular symptoms had the highest specificity (84% and 69%, respectively) and the highest percent agreement (74% and 68%) with PDAR. Identification of triggers for nasal and ocular symptoms had the highest sensitivity (89%). Positive predictive values ranged from 31 to 39%. Combining 2 responses with highest agreement increased specificity for PDAR to 91%.

CONCLUSION

Responses to hayfever and ocular symptoms had better specificity and percent agreement with PDAR than the ISAAC-validated questionnaire item. Combining 2 rhinitis questions sharply increases specificity and may improve diagnostic accuracy of clinical questions.

Effect of environmental tobacco smoke on atopic dermatitis among children in Korea

The prevalence of atopic dermatitis is increasing in many countries. Several factors are known to be associated with childhood atopic dermatitis. Environmental tobacco smoke (ETS) is one of the most common indoor pollutants, and children are more vulnerable to ETS exposure than adults are. In this study, the possible association of ETS with atopic dermatitis was evaluated in 7030 individuals aged 6-13 years who participated in the Children's Health and Environment Research study. In addition, predictive factors, such as the allergic history of the parents, children's immunoglobulin E levels and children's history of rhinitis and its association with dermatitis, were assessed. After adjustment for possible confounding variables, atopic dermatitis was found to be highly correlated with ETS, especially among children whose mothers had smoked during pregnancy and/or in the first year after birth (OR=2.06, 95% CI: 1.01-4.22). In conclusion, our results show that childhood exposure to ETS is a major risk factor for atopic dermatitis.