Effect of gestational smoke exposure on atopic dermatitis in the offspring

The Effects of Smoking on the Severity of Atopic Dermatitis in Saudi Arabia

Background Atopic dermatitis (AD) is a well-known inflammatory skin disease that is associated with a family history of other atopic diseases. Tobacco smoking has been found to affect AD as well as several other inflammatory skin diseases. In this study, we aimed to investigate this association and to elucidate the link between dose-dependent tobacco exposure and symptom severity. Methods This cross-sectional study was conducted on individuals from the general population of Riyadh, Saudi Arabia. Data were collected using an online questionnaire. All statistical analyses were performed using RStudio, version 1.1.363 (RStudio, PBC, Boston, Massachusetts, United States). Questions about the participants' age, sex, and occupational status were included. The participants were asked to report their daily handwashing habits and history of atopic diseases. Data on the smoking duration, number of cigarettes smoked per day, and passive exposure were collected. Results A total of 510 participants (41.3 %) reported having AD. Smoking was significantly associated with an increased prevalence of AD. The odds of having AD were 1.78 and 2.27 times higher in occasional smokers (odds ratio (OR) = 1.78, p < 0.05) and daily smokers (OR = 2.27, p < 0.001) than in non-smokers. Neither smoking frequency (p = 0.19) nor duration (p = 0.73) was significantly associated with AD prevalence. Conclusion Smoking is significantly associated with an increased prevalence of AD. Adults should be discouraged from smoking in order to prevent adult-onset AD. The level of nicotine exposure should be measured objectively in future studies.

Smoke exposure and childhood atopic eczema and food allergy: A systematic review and meta-analysis

BACKGROUND

There is no consensus on the effect of timing and type of smoke exposure on early allergy development. This study aimed to determine the relationship between early eczema or food allergy/hypersensitivity development in children by firstly investigating the effect of smoke exposure across critical development periods and secondly by analyzing effects of parental atcive or passive smoking.

METHODS

Four databases (PubMed, Web of Science, Scopus and Embase) were searched in May 2022 and assessed by two independent reviewers. Case-control, cross-sectional or cohort studies reporting on smoke exposure from preconception to postnatal periods and atopic eczema, food allergy and/or hypersensitivity outcomes by age 3 years were included. The Newcastle-Ottawa Scale was used to assess study quality. Random effects model was used to estimate the pooled risk ratios.

RESULTS

From 1689 identified records, 32 studies with nearly 190,000 subjects were included. Parental smoking during preconception, pregnancy and postnatal periods was generally not associated with the risk of eczema, food allergy and food sensitisation development by age 3 years. Maternal active smoking during pregnancy was negatively associated with self-reported doctor diagnosis of eczema (RR = 0.87, 95% CI 0.77-0.98; I2  = 50.56) and maternal passive smoking during pregnancy was positively associated with clinician assessment of eczema in one study (RR = 1.38; 95% CI 1.06-1.79).

CONCLUSION

Our findings highlighted the importance of in utero programming in early-life allergy development. Despite the weak evidence, our results suggest pregnant women should minimise their contact with second-hand smoke to prevent offspring eczema development. There is a need for greater utilisation of objective allergy assessments in future studies.

Aryl Hydrocarbon Receptor Repressor Is Hypomethylated in Psoriasis and Promotes Psoriasis-like Inflammation in HaCaT Cells

It is known that DNA hypomethylation of aryl hydrocarbon receptor repressor (AhRR), one of the epigenetic markers of environmental pollutants, causes skin diseases. However, the function and mechanisms are still unknown. We aimed to determine whether AhRR is hypomethylated in PBMC of psoriasis patients, as well as to examine the expression of psoriasis-related inflammatory cytokines and antimicrobial peptides after 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) treatment in HaCaT cells overexpressing or silencing AhRR. AhRR was determined by qPCR, Western blot, immunohistochemistry, and immunocytochemistry in skin tissue and HaCaT cells. DNA methylation of AhRR was performed by Infinium Human Methylation450 BeadChip in PBMC of psoriasis patients and methylation-specific PCR (MSP) in HaCaT cells. NF-κB pp50 translocation and activity were performed by immunocytochemistry and luciferase reporter assay, respectively. We verified AhRR gene expression in the epidermis from psoriasis patients and healthy controls. AhRR hypomethylation in PBMC of psoriasis patients and pAhRR-HaCaT cells was confirmed. The expression level of AhRR was increased in both TCDD-treated HaCaT cells and pAhRR-HaCaT cells. NF-κB pp50 translocation and activity increased with TCDD. Our results showed that AhRR was hypomethylated and overexpressed in the lesional skin of patients with psoriasis, thereby increasing AhRR gene expression and regulating pro-inflammatory cytokines through the NF-κB signaling pathway in TCDD-treated HaCaT cells.

Maternal Stressful Life Events during Pregnancy and Atopic Dermatitis in Children Aged Approximately 4-6 Years

The prevalence of atopic dermatitis (AD) in children has steadily increased over time, yet it remains largely unknown how maternal factors during pregnancy are associated with child AD. Few studies have specifically assessed the relationship between prenatal stress and child AD, with inconsistent findings. In this prospective cohort study following 426 mother-child dyads from pregnancy to middle childhood, women reported stressful life events (SLEs) experienced during the 12 months before delivery and AD outcomes in children aged approximately 4-6 years, including current, location-specific, and ever AD. We used Poisson regression to estimate risk ratios (RRs) and corresponding 95% confidence intervals (CIs) associated with a 1-unit increase in prenatal SLEs, adjusting for potential confounders. We also assessed whether the association between prenatal SLEs and child AD was modified by child sex, history of maternal atopy, or prenatal maternal resilient coping. The mean (standard deviation) of prenatal SLEs reported in the overall sample was 1.4 (1.6), with 37.1% of women reporting none. A 1-unit increase in prenatal SLEs was not significantly associated with current AD (RR: 1.08, 95% CI: 0.89, 1.31), location-specific AD (RR: 1.09, 95% CI: 0.78, 1.52), or ever AD (RR: 0.97, 95% CI: 0.87, 1.09). We did not find evidence of effect modification. Findings from this study suggest no association between prenatal SLEs and AD in middle childhood, although larger longitudinal studies with enhanced case definition and higher variability of SLE experience may more fully inform this question.

Multiple environmental exposures in early-life and allergy-related outcomes in childhood

INTRODUCTION

Early onset and high prevalence of allergic diseases result in high individual and socio-economic burdens. Several studies provide evidence for possible effects of environmental factors on allergic diseases, but these are mainly single-exposure studies. The exposome provides a novel holistic approach by simultaneously studying a large set of exposures. The aim of the study was to evaluate the association between a broad range of prenatal and childhood environmental exposures and allergy-related outcomes in children.

MATERIAL AND METHODS

Analyses of associations between 90 prenatal and 107 childhood exposures and allergy-related outcomes (last 12 months: rhinitis and itchy rash; ever: doctor-diagnosed eczema and food allergy) in 6-11 years old children (n = 1270) from the European Human Early-Life Exposome cohort were performed. Initially, we used an exposome-wide association study (ExWAS) considering the exposures independently, followed by a deletion-substitution-addition selection (DSA) algorithm considering all exposures simultaneously. All the exposure variables selected in the DSA were included in a final multi-exposure model using binomial general linear model (GLM).

RESULTS

In ExWAS, no exposures were associated with the outcomes after correction for multiple comparison. In multi-exposure models for prenatal exposures, lower distance of residence to nearest road and higher di-iso-nonyl phthalate level were associated with increased risk of rhinitis, and particulate matter absorbance (PM_abs) was associated with a decreased risk. Furthermore, traffic density on nearest road was associated with increased risk of itchy rash and diethyl phthalate with a reduced risk. DSA selected no associations of childhood exposures, or between prenatal exposures and eczema or food allergy.

DISCUSSION

This first comprehensive and systematic analysis of many environmental exposures suggests that prenatal exposure to traffic-related variables, PM_abs and phthalates are associated with rhinitis and itchy rash.

2,3,7,8-Tetrachlorodibenzo-p-Dioxin Regulates the Expression of Aryl Hydrocarbon Receptor-Related Factors and Cytokines in Peripheral Blood Mononuclear Cells and CD4+ T cells from Patients with Atopic Dermatitis and Psoriasis

Background

Aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor, is important for xenobiotic metabolism and binds to various endogenous and exogenous ligands in the skin. However, the functional role of AhR in patients with psoriasis (PS) and atopic dermatitis (AD) remains unclear.

Objective

We aimed to determine whether AhR-regulated factors (AhR, CYP1A1, interleukin [IL]-17, IL-22) were affected by AhR ligands (2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD) in chronic inflammatory skin diseases such as PS and AD.

Methods

The expression levels of AhR-related factors were determined by quantitative PCR, western blotting, and immunocytochemistry. Specific siRNA targeting AhR was used to inhibit gene expression in human peripheral blood mononuclear cells (PBMC). Cytokine assays were performed to determine the protein production of CD4+ T cells.

Results

In comparison with healthy controls, TCDD-treated PBMCs and CD4+ T cells from patients with PS and AD showed an increase in AhR gene levels as well as significantly increased expression of AhR-related factors (such as AhR, CYP1A1, IL-17, and IL-22). In contrast, 6-formyl indolo [3,2-b] carbazole (FICZ) inversely affected the differentiation of CD4+ T cells and their cytokine expression levels as compared with TCDD. CD4+ T cells from patients with AD and PS showed higher expression levels of AhR, CYP1A1, IL-17, and IL-22.

Conclusion

Our results suggest that TCDD-induced AhR-related factor upregulation in AD and PS patients may increase the expression of AhR-regulatory genes, thereby contributing to the development of AD and PS.

Do traditional fermented foods protect against infantile atopic dermatitis

BACKGROUND

Environmental and dietary factors during pregnancy may affect development of infantile atopic dermatitis (AD). This study analyzed whether maternal consumption of selected Turkish fermented foods (FF) and other factors during pregnancy affect the development of AD during the first 2 years of life.

METHODS

Eighty-four children with physician-diagnosed AD (aged between 2 and 24 months) and mothers, and 56 similarly aged, healthy children and mothers were studied. Physician-administered questionnaires retrospectively surveyed maternal consumption of FF during pregnancy. The intake frequency of 8 selected Turkish FF was classified as either (1) daily or (2) less than daily. Other possible demographic and environmental risk factors were also analyzed.

RESULTS

Daily maternal consumption of yogurt, fermented olive, and cheese in the control group was significantly higher than the AD group (P < 0.001, P = 0.017, and P = 0.011, respectively). Exposure to environmental tobacco smoking (ETS) was more common in the AD group than the control group (P = 0.025). In multivariate logistic regression analysis, maternal ETS exposure during pregnancy was associated with increased risk of infantile AD, and daily consumption of yogurt was associated with a reduced risk (odds ratio [OR]: 2.60, 95% confidence interval [CI]: 1.11-6.1, and OR: 0.22, CI: 0.09-0.54, respectively). The diversity of consumed FF during pregnancy was found to have a protective effect against infantile AD (OR: 0.27, CI: 0.14-0.53).

CONCLUSIONS

Daily maternal intake of yogurt and diversity of consumed Turkish FF during pregnancy may reduce the risk of AD. Maternal tobacco smoke exposure is associated with increased risk of infantile AD.

Fetal Tobacco Smoke Exposure in the Third Trimester of Pregnancy Is Associated with Atopic Eczema/Dermatitis Syndrome in Infancy

The manifestation of atopic dermatitis (AD) is initially nonatopic eczema in early infancy; the manifestations subsequently change in age-specific stages. Since allergen-specific T-helper 2 cells appear in the fetus primarily after the third trimester of pregnancy and rapidly mature during the first 6 months of life, different timings of tobacco smoke exposure may have different effects on AD. In this study, we investigated whether the timing of fetal or/and infantile tobacco smoke exposure affects the cumulative incidence of atopic eczema/dermatitis syndrome (AEDS) in infants in Japan. This cross-sectional study enrolled 1,177 parent-infant pairs, in which the infants were >6 months old. Parental allergic history, number of older siblings, physician-diagnosed AEDS and food allergy (FA), and the perinatal fetal and/or infantile tobacco smoke exposure timing after 28 weeks gestation and during the first 6 months of life were assessed using self-completed questionnaires. Fetal tobacco smoke exposure after 28 weeks gestation was significantly associated with higher cumulative incidence of AEDS in exposed infants than in unexposed infants: AEDS in all infants, 41.4% versus 34.0% (Chi-squared, P = 0.020; adjusted odds ratio, 5.21; 95% confidence interval, 1.08-25.15); AEDS in those without parental allergic history, 38.0% versus 26.6% (Chi-squared, P = 0.024). Postnatal infantile tobacco smoke exposure timing was not significantly associated with cumulative incidence of AEDS. No significant associations were observed between any tobacco smoke exposure timings and the cumulative incidence of FA. Fetal tobacco smoke exposure during the third trimester of pregnancy was positively associated with AEDS in infancy and might induce epigenetic changes in the fetal allergen-specific immune responses.

Atopic Dermatitis Studies through In Vitro Models

Atopic dermatitis (AD) is a complex inflammatory skin condition that is not fully understood. Epidermal barrier defects and Th2 immune response dysregulations are thought to play crucial roles in the pathogenesis of the disease. A vicious circle takes place between these alterations, and it can further be complicated by additional genetic and environmental factors. Studies investigating in more depth the etiology of the disease are thus needed in order to develop functional treatments. In recent years, there have been significant advances regarding in vitro models reproducing important features of AD. However, since a lot of models have been developed, finding the appropriate experimental setting can be difficult. Therefore, herein, we review the different types of in vitro models mimicking features of AD. The simplest models are two-dimensional culture systems composed of immune cells or keratinocytes, whereas three-dimensional skin or epidermal equivalents reconstitute more complex stratified tissues exhibiting barrier properties. In those models, hallmarks of AD are obtained, either by challenging tissues with interleukin cocktails overexpressed in AD epidermis or by silencing expression of pivotal genes encoding epidermal barrier proteins. Tissue equivalents cocultured with lymphocytes or containing AD patient cells are also described. Furthermore, each model is placed in its study context with a brief summary of the main results obtained. In conclusion, the described in vitro models are useful tools to better understand AD pathogenesis, but also to screen new compounds in the field of AD, which probably will open the way to new preventive or therapeutic strategies.

The LINA Study: Higher Sensitivity of Infant Compared to Maternal Eosinophil/Basophil Progenitors to Indoor Chemical Exposures

Purpose. Enhanced eosinophil/basophil (Eo/B) progenitor cell levels are known to be associated with allergic inflammation and atopy risk. The aim of the present study was to investigate the influence of different indoor exposures on the recruitment and differentiation of Eo/B progenitors in mother-child pairs. Methods. In 68 mother-child pairs of the LINA study peripheral blood mononuclear cells were used to assess Eo/B colony forming units (CFUs). Information about disease outcomes and indoor exposures was obtained from questionnaires. Indoor concentrations of volatile organic compounds (VOCs) were measured by passive sampling. Results. Infant's Eo/B CFUs were positively associated with exposure to tobacco smoke, disinfectants, or VOCs. In contrast, for maternal Eo/B CFUs, only a few associations were seen. Higher numbers of infant Eo/B CFUs were observed in children with wheezing symptoms within the second year of life. Conclusions. We demonstrate that infant's hematopoietic cells seem to respond with more sensitivity to environmental exposure compared to maternal cells. At least in infants, an activation of these hematopoietic cells by environmental exposure could contribute to an enhanced risk for the development of respiratory outcomes.

Prenatal Particulate Matter/Tobacco Smoke Increases Infants' Respiratory Infections: COCOA Study

Purpose

To investigate whether prenatal exposure to indoor fine particulate matter (PM_2.5) and environmental tobacco smoke (ETS) affects susceptibility to respiratory tract infections (RTIs) in infancy, to compare their effects between prenatal and postnatal exposure, and to determine whether genetic factors modify these environmental effects.

Methods

The study population consisted of 307 birth cohort infants. A diagnosis of RTIs was based on parental report of a physician's diagnosis. Indoor PM_2.5 and ETS levels were measured during pregnancy and infancy. TaqMan was used for genotyping of nuclear factor erythroid 2-related factor (Nrf2) (rs6726395), glutathione-S-transferase-pi (GSTP) 1 (rs1695), and glutathione-S-transferase-mu (GSTM) 1. Microarrays were used for genome-wide methylation analysis.

Results

Prenatal exposure to indoor PM_2.5 increased the susceptibility of lower RTIs (LRTIs) in infancy (adjusted odds ratio [aOR]=2.11). In terms of combined exposure to both indoor PM_2.5 and ETS, prenatal exposure to both pollutants increased susceptibility to LRTIs (aOR=6.56); however, this association was not found for postnatal exposure. The Nrf2 GG (aOR=23.69), GSTM1 null (aOR=8.18), and GSTP1 AG or GG (aOR=7.37) genotypes increased the combined LRTIs-promoting effects of prenatal exposure to the 2 indoor pollutants. Such effects of prenatal indoor PM_2.5 and ETS exposure were not found for upper RTIs.

Conclusions

Prenatal exposure to both indoor PM_2.5 and ETS may increase susceptibility to LRTIs. This effect can be modified by polymorphisms in reactive oxygen species-related genes.

Low birth weight and environmental tobacco smoke increases the risk of wheezing in adolescents: a retrospective cohort study

Background

Low birth weight (LBW) and environmental tobacco smoke (ETS) exposure are each associated with wheezing in children. This study was designed to examine the combined association of LBW and ETS with wheezing.

Methods

A retrospective birth cohort analysis linked with a national survey of allergic disorders among 1,018,031 junior high school students in Taiwan (1995–1996) was analyzed. The reported incidence of wheezing (yes or no) and ETS exposure (4 categories: 0, 1–20, 21–40 and greater than or equal to 41 household cigarettes per day) were obtained from validated questionnaires. Multiple logistic regression models were used to assess the associations of interest.

Results

There were 844,003 (83%) subjects analyzed after the exclusion criteria. LBW was associated with an increased risk of reporting ever wheezing (odds ratio [OR] = 1.08, 95% confidence interval [CI] = 1.01–1.16), current wheezing (OR = 1.09, 95% CI = 1.00–1.20) and wheezing with exercise (OR = 1.11, 95% CI = 1.02–1.21) within the smoke-free cohort. Higher ETS exposure correlated to a higher risk of wheezing (ever, current and with exercise). With ETS exposure, adolescents from the lowest birth weight cohorts were more likely to report wheezing (ever, current and with exercise).

Conclusions

ETS and LBW each has been related to increasing public health risk for respiratory symptoms among adolescents. Furthermore, LBW may aggravate the risk among those exposed to ETS. LBW, ETS and associated respiratory impairments may deserve special attention as part of a comprehensive environmental health risk assessment directed toward prevention and intervention.

Multilevel analysis of air pollution and early childhood neurobehavioral development

To investigate the association between the ambient air pollution levels during the prenatal and postnatal stages and early childhood neurobehavioral development, our study recruited 533 mother-infant pairs from 11 towns in Taiwan. All study subjects were asked to complete childhood neurobehavioral development scales and questionnaires at 6 and 18 months. Air pollution, including particulate matter ≤10 μm (PM10), carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), and hydrocarbons, was measured at air quality monitoring stations in the towns where the subjects lived. Multilevel analyses were applied to assess the association between air pollution and childhood neurobehavioral development during pregnancy and when the children were 0 to 6 months, 7 to 12 months, and 13 to 18 months old. At 18 months, poor subclinical neurodevelopment in early childhood is associated with the average SO2 exposure of prenatal, during all trimesters of pregnancy and at postnatal ages up to 12 months (first trimester β = -0.083, se = 0.030; second and third trimester β = -0.114, se = 0.045; from birth to 12 months of age β = -0.091, se = 0.034). Furthermore, adverse gross motor below average scores at six months of age were associated with increased average non-methane hydrocarbon, (NMHC) levels during the second and third trimesters (β = -8.742, se = 3.512). Low-level SO2 exposure prenatally and up to twelve months postnatal could cause adverse neurobehavioral effects at 18 months of age. Maternal NMHC exposure during the 2nd and 3rd trimesters of pregnancy would be also associated with poor gross motor development in their children at 6 months of age.

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.

The Taiwan Birth Panel Study: a prospective cohort study for environmentally- related child health

BACKGROUND

The Taiwan Birth Panel Study (TBPS) is a prospective follow-up study to investigate the development of child health and disease in relation to in-utero and/or early childhood environmental exposures. The rationale behind the establishment of such a cohort includes the magnitude of potential environmental exposures, the timing of exposure window, fatal and children's susceptibility to toxicants, early exposure delayed effects, and low-level or unknown neurodevelopmental toxicants.

METHODS

A total of 486 mother-infant paired was enrolled from April 2004 to January 2005 in this study. Maternal blood before delivery, placenta and umbilical cord blood at birth, and mothers' urine after delivery were collected. The follow-up was scheduled at birth, 4, 6 months, and 1, 2, 3 and 5 years. The children's blood, urine, hair, and saliva were collected at 2 years of age and children's urine was collected at 5 years of age as well. The study has been approved by the ethical committee of National Taiwan University Hospital. All the subjects signed the inform consent on entering the study and each of the follow up.

RESULTS

Through this prospective birth cohort, the main health outcomes were focused on child growth, neurodevelopment, behaviour problem and atopic diseases. We investigated the main prenatal and postnatal factors including smoking, heavy metals, perfluorinated chemicals, and non-persistent pesticides under the consideration of interaction of the environment and genes.

CONCLUSIONS

This cohort study bridges knowledge gaps and answers unsolved issues in the low-level, prenatal or postnatal, and multiple exposures, genetic effect modification, and the initiation and progression of "environmentally-related childhood diseases."

The role of allergic risk and other factors that affect the occurrence of atopic dermatitis in the first 6 months of life

Background

Atopic dermatitis (AD) is a chronic inflammation of the skin that often appears in early childhood. The manifestation is related to the tendency towards T helper 2 cytokine immune responses (interleukin (IL)-4, IL-5). Genetic factors are suggested to play important roles in AD, and it can be transmitted to newborns, increasing their risk of developing allergies.

Objective

To determine the association between cord-blood cytokine levels (IL-5, interferon (IFN) γ), cord-blood total immunoglobulin E (IgE) level, perinatal environmental exposure, and the risks of allergy as well as the development of AD in the first 6 months of life.

Methods

A 6-month cohort study with a nested case-control within was conducted on newborns in Jakarta from December 2008 until May 2009. After the umbilical cord blood samples were taken and stored, subjects were followed up monthly until 6 months old. The occurrence of AD and lifestyle or environmental exposures were recorded. The allergic risk was determined using a modified pediatric allergy immunology work groups scoring system based on allergic history (allergic rhinitis, asthma, AD) in the family. The levels of IL-5 and IFN-γ were measured using ELISA and total IgE by CAP system FEIA. Multivariate analysis was used to evaluate risk factors.

Results

This study was conducted on 226 subjects. The incidence of AD was 16.4%; of those, 59% had low risk allergy, 38.5% moderate, and 2% high risk. AD mostly occurred at the age of 1 month (57%). Cord blood samples were examined in 37 subjects with AD and 51 without AD; of those, 25% showed high levels of total IgE (>1.2 IU/µL), and 51% showed normally-distributed high absorbance IL-5 values (≥0.0715, absolute value was undetected). The increased level of IL-5 was directly proportional to IgE. High absorbance IFN-γ values (≥0.0795, absolute value = 18.681 pg/µL) were observed in 52% of subjects.

Conclusion

The associations between the risk of allergy in the family, cord-blood total IgE, IL-5, IFN levels, and some perinatal environmental exposure with AD in the first 6 months of life have not been established.

Maternal signals for progeny prevention against allergy and asthma

Allergy and asthma are chronic inflammatory diseases which result from complex gene-environment interactions. Recent evidence indicates the importance of prenatal and postnatal developmental processes in terms of maturation of balanced immune responses. According to the current view, gene-environment interactions during a restricted time frame are responsible for programming of the immune system in favor of allergic immune mechanisms later in life. The interaction between genes and environment is complex and only partially understood; however, heritable epigenetic modifications including chemical additions in and alternative packaging of the DNA have been shown to play a crucial role in this context. Novel data indicate that epigenetic mechanisms contribute to the development of T-helper cell function. Environmental factors, including diesel exhaust particles (DEP), vitamins and tobacco smoke, operate through such mechanisms. Furthermore, the role of environmental microbes provides another and maybe even more important group of exogenous exposures which operates in this critical time frame.

Lifetime exposure to cigarette smoking and the development of adult-onset atopic dermatitis

BACKGROUND

Adult-onset atopic dermatitis (AD) has recently been recognized as a distinct disease entity, but its risk factors have not yet been clearly defined. Although gestational and perinatal exposure to tobacco smoking may be associated with the development of classic AD, the association between active/passive smoking and adult-onset AD remains controversial.

OBJECTIVES

To determine if exposure to smoking, including environmental tobacco smoke (ETS), is associated with the risk of adult-onset AD.

METHODS

Tobacco smoking and exposure to ETS were measured in a case-control association analysis in 83 patients with physician-diagnosed adult-onset AD and 142 age- and sex-matched controls.

RESULTS

Multiple logistic regression analyses showed that, among the potential environmental risk factors, both current and ever smoking were significant risk factors for adult-onset AD [odds ratio (OR) 4·994 and 3·619, respectively], compared with never smoking. Also, packs per year was significantly associated with adult-onset AD (OR 1·058, 95% confidence interval 1·028-1·089), suggesting a lifelong cumulative risk in current smokers. Moreover, nonsmokers with adult-onset AD reported significantly more exposure to ETS.

CONCLUSIONS

Early and/or current exposure to cigarette smoking may contribute cumulatively to the development of adult-onset AD. Exposure to ETS in childhood is associated with the development of adult-onset AD. Adults should be discouraged from smoking to prevent adult-onset AD in themselves and their family members.

Eczema in early life: genetics, the skin barrier, and lessons learned from birth cohort studies

Eczema is a chronic inflammatory disorder of the skin that affects up to 30% of children. It often afflicts infants in the first few months of life and can be the first indicator of the atopic march. Recent results from birth cohort studies have uncovered novel information regarding genetic and environmental factors that promote the development of eczema. Birth cohort studies provide an optimal study design to elucidate these associations and prospectively track longitudinal data including exposure assessment and health outcomes from birth into early life and childhood. This is especially relevant for eczema given the age specific emergence of this disease. In this review, we will provide a general overview of pediatric eczema and discuss the important findings in the literature with respect to genetics and environmental exposures, highlighting those derived from birth cohort studies. Additionally, we will review how these relate to the atopic march, the hygiene hypothesis and the integrity of the skin barrier.