Do early-life exposures explain why more advantaged children get eczema? Findings from the U.K. Millennium Cohort Study

Maternal tobacco exposure during pregnancy and atopic dermatitis in offspring: A systematic review and meta-analysis

The main purpose of this review was to examine the evidence of the relationship between active smoking or passive smoking during pregnancy and atopic dermatitis in offspring. The protocol was written following the PRISMA Checklist and was registered in the PROSPERO database (registration number CRD42022381136). We implemented a comprehensive search in PubMed, Embase and Web of Science databases to identify all potentially related articles from inception through 1 December 2022. We assessed cohort studies and case-control studies using the Newcastle-Ottawa Scale (NOS), and the Joanna Briggs Institute (JBI) critical appraisal tool to assess the quality of cross-sectional studies. Heterogeneity was investigated by using Cochrane Q tests and I2 statistics. In addition, according to the research design, population source and population size, the reasons for the heterogeneity were analysed. A total of 15 observational studies were included in this analysis. Our meta-analysis suggests that atopic dermatitis in offspring is not associated with active smoking during pregnancy (pooled OR, 0.96 [95% CI 0.86-1.07]); however, it is related to passive smoking (OR, 1.52 [95% CI 1.36-1.70]). Passive smoking during pregnancy is associated with an increased risk of eczema development in offspring. More research is needed to explore the risk of active smoking and eczema development in offspring, especially the association between measurements of pregnancy cotinine levels in maternal body fluids and AD in offspring.

Environmental Influences on Atopic Eczema

The health outcomes of an individual are shaped by a combination of genetic predisposition and environmental influences. While some diseases stem solely from environmental factors, others like atopic eczema, also known as neurodermatitis or atopic dermatitis, are multifaceted, with environmental variables playing a significant role in its initiation and severity. Atopic eczema is a prevalent chronic condition observed globally, particularly in Western industrialized nations where its prevalence is estimated to range from 2.5% to 3.5% in adults and 10% to 15% among children. The increasing incidence of atopic eczema in industrialized countries over recent decades suggests that this trend may be due to environmental changes rather than genetic predispositions. Therefore, by thoroughly examining environmental factors and their role in atopic dermatitis, one may be able to gain a better understanding of its disease pattern and develop possible preventative measures. This article provides a comprehensive analysis of how the surrounding environment contributes to the pathogenesis of atopic eczema.

Atopic dermatitis, cognitive function and psychiatric comorbidities across early childhood and adolescence in a population-based UK birth cohort

BACKGROUND

Atopic dermatitis (AD) may affect cognitive function, but studies are limited and inconsistent. The effect of AD severity on cognition remains underexplored and few previous studies have examined clinically validated or repeated measures of cognition throughout childhood.

OBJECTIVES

To evaluate the relationship of AD activity and severity with validated measures of general cognition in a longitudinal birth cohort.

METHODS

We conducted cross-sectional analyses using data from the Avon Longitudinal Study of Parents and Children (ALSPAC), a UK cohort of 14 975 individuals followed prospectively since their birth in 1991-92. AD was assessed 11 times between the age of 6 and 166 months. Mothers were asked if their child had an 'itchy, dry skin rash in the joints and creases', and AD status was time-updated accordingly as 'never', 'maybe', 'inactive', 'active/mild' or 'active/moderate-severe'. General cognition [i.e. intelligence quotient (IQ)] was measured at 18, 49, 103 and 186 months of age using the Griffiths Mental Development Scales (GMDS), Wechsler Preschool and Primary Scale of Intelligence (WPPSI), Wechsler Intelligence Scale for Children (WISC) and Wechsler Abbreviated Scale of Intelligence (WASI), respectively. Multivariable linear regression was used to compare IQ with respect to nearest time-updated AD status. Secondary analyses were stratified by the presence or absence of psychiatric or learning disorders. An exploratory longitudinal analysis of IQ across all four outcome assessments was conducted using generalized estimating equations.

RESULTS

No significant associations between AD status and full-scale IQ scores on the GMDS, WPPSI, WISC and WASI were observed after adjustment for sociodemographic factors, atopic comorbidities and sleep characteristics. However, at 8 years of age, WISC Performance IQ was slightly, although statistically significantly, lower among children with active/moderate-severe AD [β coefficient -2.16, 95% confidence interval (CI) -4.12 to -0.19] and Verbal IQ was slightly, but statistically significantly, higher among those with inactive AD (β coefficient 1.31, 95% CI 0.28-2.34) compared with those without AD. Analyses stratified by psychiatric or learning disorders, and exploratory longitudinal analyses of cognition revealed similar findings.

CONCLUSIONS

We did not find any clinically meaningful associations between AD activity and severity and general cognitive function during early childhood and adolescence. Future studies should incorporate objective measures of AD severity and investigate outcomes beyond IQ.

Atopic Dermatitis: Disease Background and Risk Factors

Multiple risk factors have been associated with the development of atopic dermatitis (AD). Recent advances in understanding the role of genetics in this disease have been made, with discovery of the filaggrin (FLG) gene as the most notable so far. In addition to FLG gene mutations as a risk factor for AD, a positive family history of atopic or allergic disease in either parent has been shown to confer a greater risk of developing AD. Atopic dermatitis usually presents early in life and is thought to represent the initial step in the "atopic march," which is characterized by the development of other atopic diseases later in life such as asthma, allergic rhinitis, and/or rhinoconjunctivitis, food allergies, and hay fever. Other comorbid diseases that have been associated with AD include increase risk of viral and bacterial skin infections, neuropsychiatric diseases such as attention-deficit hyperactivity disorders (ADHD), and autistic spectrum disorder (ASD). Patients with AD have also been found to have worse sleep quality overall compared to patients without AD. In this chapter, we will discuss the risk factors associated with development of atopic dermatitis as well as the most commonly reported comorbidities in patients with this disease.

Optimal timing of introduction of complementary feeding: a systematic review and meta-analysis

CONTEXT

The timing of introducing complementary feeding (CF) is crucial because premature or delayed CF can be associated with adverse health outcomes in childhood and adulthood.

OBJECTIVE

This systematic review aims to evaluate the impact of the timing of CF introduction on health, nutrition, and developmental outcomes among normal-term infants.

DATA SOURCES

Electronic databases and trial registries were searched, along with the reference lists of the included studies and relevant systematic reviews.

DATA EXTRACTION

Two investigators independently extracted data from the included studies on a standardized data-extraction form.

DATA ANALYSIS

Data were meta-analyzed separately for randomized controlled trials (RCTs) and observational studies on the basis of early introduction of CF (< 3 months, < 4 months, < 6 months of age) or late introduction of CF (> 6 months, > 8 months of age). Evidence was summarized according to GRADE criteria. In total, 268 documents were included in the review, of which 7 were RCTs (from 24 articles) and 217 were observational studies (from 244 articles). Evidence from RCTs did not suggest an impact of early introduction, while low-certainty evidence from observational studies suggested that early introduction of CF (< 6 months) might increase body mass index (BMI) z score and overweight/obesity. Early introduction at < 3 months might increase BMI and odds of lower respiratory tract infection (LRTI), and early introduction at < 4 months might increase height, LRTI, and systolic and diastolic blood pressure (BP). For late introduction of CF, there was a lack of evidence from RCTs, but low-certainty evidence from observational studies suggests that late introduction of CF (> 6 months) might decrease height, BMI, and systolic and diastolic BP and might increase odds of intestinal helminth infection, while late introduction of CF (> 8 months) might increase height-for-age z score.

CONCLUSION

Insufficient evidence does suggest increased adiposity with early introduction of CF. Hence, the current recommendation of introduction of CF should stand, though more robust studies, especially from low- and middle-income settings, are needed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42020218517.

Timing of introduction to solid food, eczema and wheezing in later childhood: a longitudinal cohort study

BACKGROUND

The timing of introduction to solid food has been associated with eczema and wheezing in childhood. Our aim was to determine whether differences persist within the recommended 4 to 6 month age range.

METHODS

A longitudinal cohort study with repeated measures was conducted among children from birth to 10 years of age who were participating in the TARGet Kids! practice based research network in Toronto, Canada. The primary exposure was the timing of introduction to infant cereal as the first solid food. The primary outcome was eczema and the secondary outcome was wheezing collected by parent report using the validated International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Multinomial generalized estimating equations were used and effect modification by family history of asthma and breastfeeding duration were explored.

RESULTS

Of the 7843 children included, the mean (standard deviation) age of introduction to infant cereal was 5.7 (1.9) months. There was evidence for family history of asthma and breastfeeding duration to be effect modifiers in the eczema (P = 0.04) and wheezing (P = 0.05) models. Introduction to infant cereal at 4 vs. 6 months of age was associated with higher odds of eczema (OR 1.62; 95% CI: 1.12, 2.35; P = 0.01) among children without a family history of asthma who were not breastfeeding when solid foods were introduced. Introduction to infant cereal at 4 vs. 6 months of age was associated with a higher odds of wheezing (OR 1.31; 95% CI: 1.13, 1.52; P < .001) among children without a family history of asthma who were breastfeeding when solid foods were introduced. There was little evidence of an association among the remaining strata for either outcome.

CONCLUSION

The findings of this study support recommendations to introduce solid food around 6 months of age.

Investigating causal relationships between genetically determined increased risk of attention-deficit/hyperactivity disorder (ADHD) and atopic dermatitis (AD): A Mendelian randomization analysis

Atopic dermatitis (AD) is a chronic, inflammatory skin condition with a huge disease burden. Attention-deficit/hyperactivity disorder (ADHD) is often diagnosed in children, and is associated with symptoms of inattention, hyperactivity and impulsive behaviour. Observational studies have demonstrated associations between AD and ADHD. However, to date, there has been no formal assessment of causal relationship between the two. We aim to evaluate causal relationships between genetically increased risk of AD and ADHD using Mendelian randomization (MR) approach. Two-sample bi-directional MR was conducted to elucidate potential causal relationships between genetically increased risk of AD and ADHD, using the largest and most recent genome-wide association study datasets for AD and ADHD-EArly Genetics & Lifecourse Epidemiology AD consortium (21 399 cases and 95 464 controls) and Psychiatric Genomics Consortium (20 183 cases and 35 191 controls). Genetically determined increased risk of AD is not associated with ADHD based on genetic information: odds ratio (OR) of 1.02 (95% CI -0.93 to 1.11; p = 0.705). Similarly, genetic determined increased risk of ADHD is not associated with an increased risk of AD: OR of 0.90 (95% CI -0.76 to 1.07; p = 0.236). Horizontal pleiotropy was not observed from the MR-Egger intercept test (p = 0.328) Current MR analysis showed no causal relationship between genetically increased risk of AD and ADHD in either direction in individuals of European descent. Any observed associations between AD and ADHD in previous population studies could possibly be due to confounding lifestyle factors such as psychosocial stress and sleeping habits.

Prenatal Maternal Risk Factors Contributing to Atopic Dermatitis: A Systematic Review and Meta-Analysis of Cohort Studies

BACKGROUND

The gestational risk factors predispose to the manifestation of early childhood atopic dermatitis (AD).

OBJECTIVE

We evaluated the association between modifiable and non-modifiable gestational and prenatal risk factors that affect the AD prevalence in children.

METHODS

We performed the systematic review and meta-analysis of cohort studies (n=27) in PubMed and EMBASE (2000~2021). A meta-analysis was performed using random-effects models to estimate pooled odds ratios (OR) or hazard ratio (HR). We performed a systematic review according to Preferred Reporting Item for Systematic Review and Meta-Analyses (PRISMA) guidelines and summarized cohort studies investigating gestational and prenatal risk factor those predispose to AD in off spring. Leading modifiable and non-modifiable were identified through ORs. Meta-analysis using the random effect model was also conducted to provide an overall estimate for several significant factors.

RESULTS

Among the non-modifiable risk factors gestational diabetes (7.2, 95% confidence interval [CI]: 1.4~34.5), maternal history of allergy (2.14, 95% CI: 1.54~2.97) and prenatal history of eczema (2.46, 95% CI: 1.0~5.8) were found as major determining risk factors in early manifestation of AD in children. Further, maternal exposure to industrial products (1.89, 95% CI: 1.10~3.16), exposure to antibiotics during pregnancy (3.59, 95% CI: 1.19~10.85) and passive smoking during pregnancy (2.60, 95% CI: 1.11~6.1) are leading causes of early AD manifestation.

CONCLUSION

Conclusively, both genetic and environmental factors play a pivotal role in early manifestation of AD. The better managing the environmental factors during gestational phase to the least can help curtail the prevalence of AD in children.

Effects of Residential Environment and Lifestyle on Atopic Eczema Among Preschool Children in Shenzhen, China

Eczema, one of the most prevalent inflammatory skin diseases among children, is potentially influenced by genetic, environmental and social factors. However, few studies have investigated the effect of residential environment and lifestyle on childhood eczema. Therefore, this study conducted a cross-sectional study based on 2,781 preschool children in Shenzhen, China, during 2015–2016. Logistic regression models were employed to analyze the associations between residential/household environment, lifestyle, dietary habits and eczema in children. The prevalence of eczema among children in Shenzhen was 24.6%. Significant associations (increased odds >50%, P < 0.05) were found between childhood eczema and the factors of using composite wood floors (adjusted OR = 1.777 for doctor-diagnosed eczema, 1.911 for eczema-like symptoms), living in a villa/townhouse (aOR = 3.102, 2.156), the presence of mold or damp stains in the child's room (aOR = 1.807, 2.279), and rarely cleaning the child's room (aOR = 1.513, 1.540). In addition, watching TV/playing computer games for more than one hour per day was significantly associated with eczema (aOR = 1.172, 1.174). Notably, we found that eating rice/pasta one to three times per week may elevate the risk of eczema-like symptoms (aOR = 1.343), which warrants further investigation. In addition, ambient air pollution, in the covariates, may also affect childhood eczema. Therefore, avoiding these adverse factors and creating a low-risk environment are crucial to prevent childhood eczema.

Antibiotic exposure and adverse long-term health outcomes in children: a systematic review and meta-analysis

BACKGROUND

Antibiotics are among the most commonly used drugs in children. In addition to inducing antibiotic resistance, antibiotic exposure has been associated with long-term adverse health outcomes.

METHODS

A systematic search using PRISMA Guidelines to identify original studies reporting associations between antibiotic exposure and long-term adverse health outcomes in children. Overall pooled estimates of the odds ratios (ORs) were obtained using fixed or random-effects models.

RESULTS

We identified 160 observational studies investigating 21 outcomes in 22,103,129 children. Antibiotic exposure was associated with an increased risk of atopic dermatitis (OR 1.40, 95% confidence interval (CI) 1.30-1.52, p<0.01), allergic symptoms (OR 1.93, 95%CI 1.66-2.26, p<0.01), food allergies (OR 1.35, 95%CI 1.20-1.52, p<0.01), allergic rhinoconjunctivitis (OR 1.66, 95%CI 1.51-1.83, p<0.01), wheezing (OR 1.81, 95%CI 1.65-1.97, p<0.01), asthma (OR 1.96, 95%CI 1.76-2.17, p<0.01), increased weight gain or overweight (OR 1.18, 95%CI 1.11-1.26, p<0.01), obesity (OR 1.21, 95%CI 1.05-1.40, p<0.01), juvenile idiopathic arthritis (OR 1.74, 95%CI 1.21-2.52, p<0.01), psoriasis (OR 1.75, 95%CI 1.44-2.11, p<0.01), autism spectrum disorders (OR 1.19, 95%CI 1.04-1.36, p=0.01) and neurodevelopment disorders (OR 1.29, 95%CI 1.09-1.53, p<0.01). Dose-response effects and stronger effects with broad-spectrum antibiotic were often reported. Antibiotic exposure was not associated with an altered risk of allergic sensitisation, infantile colic, abdominal pain, inflammatory bowel disease, celiac disease, type 1 diabetes, fluorosis, and attention deficit hyperactivity disorder.

CONCLUSION

Although a causal association cannot be determined from these studies, the results support the meticulous application of sound antibiotic stewardship to avoid potential adverse long-term health outcomes.

Association of Childhood Atopic Dermatitis With a Higher Risk of Health Care Utilization and Drug Use for Asthma: A Nationwide Cohort Study

BACKGROUND

Overwhelming evidence supports a causal relationship between occurrence of asthma and atopic dermatitis (AD).

OBJECTIVE

The aims of the study were to determine the incidence of asthma in children with AD and to examine the health care utilization and drug use for asthma in children with AD.

METHODS

Children with hospital-diagnosed AD (cases) were matched with individuals from the background population (controls) in a 1:4 ratio.

RESULTS

In the final cohort (18,625 cases and 74,500 controls), the incident cases of asthma were 4203 among AD cases and 5298 in controls, corresponding to incidence rates of 34 and 9 in cases and controls per 1000 person-years, respectively (hazard ratio [HR] = 3.82, 95% confidence interval [CI] = 3.65-4.00). During the 1-year follow-up period from asthma diagnosis, children with concomitant AD had a significantly higher risk of hospital admission (HR = 1.97, 95% CI = 1.63-2.37), emergency department visits (HR = 1.62, 95% CI = 1.22-2.14), outpatient visits (HR = 1.97, 95% CI = 1.74-2.23), asthma medication (HR = 1.31, 95% CI = 1.27-1.35), and rescue course corticosteroids (HR = 1.74, 95% CI = 1.13-2.69) compared with children with asthma only.

CONCLUSIONS

The risk of being diagnosed with asthma was higher in children with AD. Risk of health care utilization and drug use for asthma was higher in children with both AD and asthma compared with asthma only.

Environmental Exposure and Childhood Atopic Dermatitis in Shanghai: A Season-Stratified Time-Series Analysis

BACKGROUND

Childhood atopic dermatitis (AD) is an inflammatory skin disease which sometimes predisposes to allergies. Environmental factors (low humidity, irritants, etc.) are prominent causative triggers of AD.

OBJECTIVES

This study aims to explore the effects of both meteorological factors and air pollutants on childhood AD, and the modification effects by season in Shanghai, China.

METHODS

Quasi-Poisson generalized linear regression model, combined with a distributed lag nonlinear model was used to examine the nonlinear and lagged effects of environmental factors on childhood AD from 2009 to 2017 in Shanghai. We also performed a season-stratified analysis to determine the modification effects of environmental exposure by season on childhood AD.

RESULTS

There were 1,043,240 outpatient visits for childhood AD in total, at 3 major pediatric hospitals. Low temperature and relative humidity (RH), and high daily temperature difference (DTD) and air pollutants (i.e., NO2) increased the relative risks (RRs) of outpatient visits for childhood AD in the whole year. In the cold season, an increased risk of outpatient visits for childhood AD was associated with low RH (RR 2.26, 95% CI 1.69-3.02) and high NO2 (1.11, 95% CI 1.06-1.17). In the warm season, outpatient visits for childhood AD were associated with low temperature (3.49, 95% CI 3.22-3.77), low RH (1.89, 95% CI 1.74-2.06), high DTD (1.41, 95% CI 1.31-1.53), and high NO2 (1.05, 95% CI 1.03-1.06).

CONCLUSIONS

This study suggests that environmental exposure may be a key trigger for outpatient visits for childhood AD with apparent seasonal effects. Tailored preventive strategies to avoid environmental triggers of childhood AD should be developed.

Global differences in atopic dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disorder, with a highly variable prevalence worldwide. Recent evidence, however, has shown an increase in prevalence in the Asia Pacific region. Nevertheless, most of the published literature has focused mainly on Western populations, and only few clinical trials have included subgroups of other ethnic populations. Reasons for the observed ethnic and geographical differences in AD are not well established. This calls into question the need for a better understanding of AD pathogenesis and inter-ethnic differences in clinical and immuno-phenotypes. These differences may reflect inherent variability in disease mechanisms between populations, which in turn may impact upon treatment responses such as biologics that are currently tailored mainly to a specific immuno-phenotype (T-helper type 2 dominant). In this article, we reviewed existing literature on the prevalence of AD globally, highlighting differences, if any, in the clinical and immuno-phenotypes of AD between different ethnicities. We discussed genetic and environmental factors that affect AD in different populations and therapeutic considerations. Our review highlights AD as a disease with ethnic-dependent clinical and immunological heterogeneity and calls for greater inclusion of ethnic diversity in future research in order to develop targeted treatments.

Altered Gut Microbiome and Environmental Factors Associated with Development of Eczema in Hong Kong Infants: A 4-Month Pilot Study

Eczema is a multifactorial skin disease that affects 20% of children worldwide and has a complex relationship with microbial, nutritional, parental and environmental factors. In this study, we investigated the potential association of eczema with the gut microbiome and environmental factors. One hundred and fifty-two newborn subjects and their mothers were recruited within 10 days postnatally at the Prince of Wales Hospital in Hong Kong, China and asked to complete questionnaires on allergies, maternal diet and environmental assessment at enrolment. Then, the participants were classified as with or without eczema at four months after birth based on the Comprehensive Early Childhood Allergy Questionnaire (CECAQ) and SCORing Atopic Dermatitis (SCORAD) index (n = 48, with 24 in each group). Stool samples were collected from both groups at the same time. Microbial DNA was extracted from each stool sample, and 16S rRNA sequencing was performed to analyze the gut microbiome profiles of the subjects. Our results indicated that the abundance of Bifidobacterium was significantly higher in the eczema group than in the control group (p = 0.04). A multivariable logistic regression analysis was conducted, and the results showed that the father’s education level and maternal intake of cereal products and nutritional supplements during pregnancy were associated with the development of eczema (p = 0.008, 0.032 and 0.015, respectively). In conclusion, this study provided preliminary information about the potential risk factors of eczema development in Hong Kong infants in support of a future full study.

Genetic predisposition and environmental factors associated with the development of atopic dermatitis in infancy: a prospective birth cohort study

The influence of environmental factors on atopic dermatitis (AD) has been investigated in many cross-sectional studies. It remains however unclear if they could influence AD development early in life. This prospective birth cohort study aimed to monitor aspects of family lifestyle and child's nutrition within a Caucasian population and to assess its association with AD development over the first 2 years of life. Genetic predisposition was evaluated based on family history and profilaggrin genotyping. Of 149 included children, 36 developed AD. Infants with a family history of atopy developed AD 2.6 times more frequently (30 of 97) than infants without atopic predisposition (6 of 52). Genotyping was carried out on 50% of the children included. Profilaggrin mutations (R501X, 2282del4, R2447X, and S3247X) were infrequent in our population. Lower incidence of AD was observed in infants exposed to a damp housing environment, lower household income, and smoking mothers with a higher but not with a lower education level.Conclusion: Family history of atopy was a significant risk factor for AD regardless of the most common, currently defined, FLG mutations. Humidity at home and passive smoking seem associated with AD development in infancy. What is Known: • Atopic dermatitis (AD) is associated with mutations in various genes of the immune system and the epidermal barrier complex in particular filaggrin (FLG) mutation. • Inherited factors alone cannot explain the rising AD; environmental factors are therefore likely to play a decisive role in this rise but the exact role that these factors may play in increasing AD risk in infancy remains unclear. Moreover, the relationship between environmental factors and AD has been the focus of mostly cross-sectional studies and not prospective studies. What is New: • This prospective birth cohort study demonstrates that family history of atopy is a significant risk factor for AD regardless of the most common, currently defined, FLG mutations. • A lower incidence of AD was observed in infants exposed to a moist housing environment, lower household income, and smoking of mothers with a higher but not with a lower education level.

Socioeconomic disadvantage and health in early childhood: a population-based birth cohort study from Portugal

BACKGROUND

Measuring early socioeconomic inequalities in health provides evidence to understand the patterns of disease. Thus, our aim was to determine which children's health outcomes are patterned by socioeconomics and to what extent the magnitude/direction of the differences vary by socioeconomic measure and outcome.

METHODS

Data on early childhood (4 years) health was obtained from Generation XXI birth cohort (n = 8647). A total of 27 health outcomes and 13 socioeconomic indicators at the individual level and neighbourhood level were used to calculate the relative index of inequality (RII).

RESULTS

Socioeconomic inequalities were evident across 21 of the 27 health outcomes. Education, occupation and income more often captured inequalities, compared with neighbourhood deprivation or employment status. Using highest maternal education as reference category, we observed that seizures (RII = 8.64), obesity (2.94), abdominal obesity (2.66), urinary tract infection (2.26), language/speech problems (2.24), hypertension (2.08) and insulin resistance (1.33) were heavily socially patterned, much more common in disadvantaged children. Contrastingly, eczema (0.26) and rhinitis (0.26) were more common among more advantaged children.

CONCLUSIONS

Socioeconomic inequalities were evident for almost every health outcome assessed, although with varying magnitude/direction according to the socioeconomic indicator and outcome. Our results reinforce that the social gradient in health manifests early in childhood.

Pediatric Allergic Diseases, Food Allergy, and Oral Tolerance

Pediatric allergic disease is a significant health concern worldwide, and the prevalence of childhood eczema, asthma, allergic rhinitis, and food allergy continues to increase. Evidence to support specific interventions for the prevention of eczema, asthma, and allergic rhinitis is limited, and no consensus on prevention strategies has been reached. Randomized controlled trials investigating the prevention of food allergy via oral tolerance induction and the early introduction of allergenic foods have been successful in reducing peanut and egg allergy prevalence. Infant weaning guidelines in the United Sates were recently amended to actively encourage the introduction of peanut for prevention of peanut allergy.

The relationship of prenatal antibiotic exposure and infant antibiotic administration with childhood allergies: a systematic review

Background

Early antibiotic exposure may be contributing to the onset of childhood allergies. The main objective of this study was to conduct a systematic review on the relationship between early life antibiotic exposure and childhood asthma, eczema and hay fever.

Methods

Pubmed and Embase were searched for studies published between 01-01-2008 and 01-08-2018, examining the effects of (1) prenatal antibiotic exposure and (2) infant antibiotic administration (during the first 2 years of life) on childhood asthma, eczema and hay fever from 0 to 18 years of age. These publications were assessed using the Newcastle Ottawa Scale (NOS) and analysed narratively.

Results

(1) Prenatal antibiotics: Asthma (12 studies): The majority of studies (9/12) reported significant relationships (range OR 1.13 (1.02–1.24) to OR 3.19 (1.52–6.67)). Three studies reported inconsistent findings. Eczema (3 studies): An overall significant effect was reported in one study and in two other studies only when prenatal antibiotic exposure was prolonged. (2) Infant antibiotics: Asthma (27 studies): 17/27 studies reported overall significant findings (range HR 1.12 (1.08–1.16) to OR 3.21 (1.89–5.45)). Dose-response effects and stronger effects with broad-spectrum antibiotic were often reported. 10/27 studies reported inconsistent findings depending on certain conditions and types of analyses. Of 19 studies addressing reverse causation or confounding by indication at least somewhat, 11 reported overall significant effects. Eczema (15 studies): 6/15 studies reported overall significant effects; 9 studies had either insignificant or inconsistent findings. Hay fever (9 studies): 6/9 reported significant effects, and the other three insignificant or inconsistent findings. General: Multiple and broad-spectrum antibiotics were more strongly associated with allergies. The majority of studies scored a 6 or 7 out of 9 based on the NOS, indicating they generally had a medium risk of bias. Although most studies showed significant findings between early antibiotic exposure and asthma, the actual effects are still unclear as intrapartum antibiotic administration, familial factors and confounding by maternal and child infections were often not addressed.

Conclusions

This review points to a moderate amount of evidence for a relationship between early life antibiotics (especially prenatal) and childhood asthma, some evidence for a relationship with hay fever and less convincing evidence for a relationship with eczema. More studies are still needed addressing intra-partum antibiotics, familial factors, and possible confounding by maternal and childhood infections. Children exposed to multiple, broad-spectrum antibiotics early in life appear to have a greater risk of allergies, especially asthma; these effects should be investigated further.

Baseline characteristics, disease severity and treatment history of patients with atopic dermatitis included in the German AD Registry TREATgermany

BACKGROUND

The Atopic Dermatitis (AD) TREATgermany registry was initiated by the German Society for Dermatology (DDG) in 2011 to evaluate the 'real-life' situation of health care for patients with AD.

OBJECTIVES

Interim data analysis on baseline characteristics as well as current and prescribed systemic treatments of the TREATgermany registry patients.

METHODS

Patients (≥18 years) with moderate-to-severe AD [objective (o)SCORAD > 20], or with current or previous anti-inflammatory systemic treatment for AD within 24 months, were included and are followed up over at least 24 months. To assess clinical signs, the eczema area severity index (EASI, 0-72), the oSCORAD (0-83) and the Investigator Global Assessment (IGA; 6-point scale) were used. The disease severity was globally scored by the patients [Patient Global Assessment (PGA); six-step Likert scale]. Disease symptoms were assessed by the patient-oriented eczema measure (POEM, 0-28) and numeric rating scales (NRS, 0-10). Health-related quality of life was measured using the dermatological life quality index (DLQI, 0-30).

RESULTS

A total of 612 patients were recruited across 32 sites between 06/2016 and 01/2019 (mean age: 42.6 ± 14.2 years; mean oSCORAD: 40.8 ± 16.3). The mean POEM score was 16.3 ± 7.5. Pruritus was rated highest among subjective symptoms (NRS: 5.4 ± 2.7). The mean DLQI value was 11.3 ± 7.5. The frequency of arterial hypertension was lower (20.8%) compared with the general population, whilst this was higher for depression (10%). More than 60% of the patients had received systemic glucocorticosteroids, and 36.8% had received cyclosporine A prior to inclusion. Dupilumab was the leading substance documented as either 'current' (12.1%) or 'prescribed' (31.4%) at baseline.

CONCLUSIONS

These 'real-life' data clearly demonstrate the substantial disease burden. Most of TREATgermany patients were already treated with or prescribed dupilumab at baseline. Moreover, current findings indicate the urgent need for further alternative agents in order to achieve a perceptible improvement of quality of life of patients with moderate-to-severe AD.

Epidemiology and associated factors of atopic dermatitis in Malagasy children

Background

Little is known about the epidemiology and associated factors of childhood AD in the markedly different, low-income, tropical environment like Madagascar.

Methods

We aim to assess the epidemiology and associated factors of AD in individuals fewer than 15 years of age in Antananarivo Madagascar. It was a retrospective and descriptive study over a period of 7 years (2010 to 2016) in children 6 months to 14 years in the Department of Dermatology, Joseph Raseta Befelatanana Antananarivo Madagascar. The diagnosis of AD was based on clinical data.

Results

The prevalence of AD was 5.6% in children aged 6 months to 14 years. The details of 151 cases of atopic dermatitis were analyzed. The mean age of patients was 4 years. There was a female preponderance (sex ratio: 0.7). A family history of AD was noted in 56 cases (37%). No association between breast-feeding and AD was found. The age of onset of AD was before the age of 3 months in 7.5% and between 6 months to 5 years in 70%. Children born in March (dry season) had the highest risk of AD. Consultations for AD increased during the winter (from July to October; p = 0.005). However, the prevalence of AD was similar in urban and rural areas.

Conclusion

Weather may have an impact on the prevalence of atopic dermatitis in Madagascar. No significant correlation was found between the duration of breastfeeding and AD, as well as urbanization.

How does parental history of atopic disease predict the risk of atopic dermatitis in a child? A systematic review and meta-analysis

BACKGROUND

Parental history of atopic disease is a well-established risk factor for the development of atopic dermatitis (AD), but several aspects of this association remain unclear.

OBJECTIVE

We sought to determine the association of parental history of atopic disease with AD in offspring.

METHODS

We searched PubMed and EMBASE through June 2018 for relevant records and adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Pooled odds ratios (ORs) with 95% CI were calculated using random-effects models.

RESULTS

A total of 163 records covering 149 unique studies were included. Of these, 119 studies were included in the meta-analysis. Individuals with parental history of atopic disease had increased odds of AD (OR, 1.81; 95% CI, 1.65-1.99). Parental asthma (OR, 1.56; 95% CI, 1.18-2.05) and allergic rhinitis (OR, 1.68; 95% CI, 1.34-2.11) had a smaller effect than AD (OR, 3.30; 95% CI, 2.46-4.42). The effect of maternal and paternal history was comparable for all atopic diseases. An increase in odds was observed when comparing the effect of having 1 (OR, 1.30; 95% CI, 1.15-1.47) or 2 atopic parents (OR, 2.08; 95% CI, 1.83-2.36), as well as having a parent with 1 (OR, 1.49; 95% CI, 1.28-1.74) or more atopic diseases (OR, 2.32; 95% CI, 1.92-2.81).

CONCLUSIONS

This study provides evidence-based risk estimates that may guide physicians who counsel parents with a history of atopic disease about their children's risk of AD. This information is of particular importance for future efforts toward establishing prophylactic interventions for AD on a general population level.

Breastfeeding duration modifies the effect of smoking during pregnancy on eczema from early childhood to adolescence

BACKGROUND

Cigarette smoke contains compounds similar to coal tar, an ancient remedy of eczema. Some studies have reported protective effects of maternal gestational smoking on offspring eczema; however, others have shown no or increased risks. Similarly, studies linking breastfeeding duration and eczema have demonstrated contradictory findings. No study has yet investigated combined effects of these two factors on eczema.

OBJECTIVE

Since tobacco compounds can pass to offspring via breast milk, we investigated their combined effects on eczema development from childhood to adolescence.

METHODS

We obtained information regarding gestational smoking, exclusive breastfeeding duration, and eczema at ages 1-or-2, 4, 10, and 18 years from the Isle of Wight (IOW) birth cohort, UK. Using generalized estimating equations, we assessed the interaction of gestational smoking and residual exclusive breastfeeding duration (Resid-BF-duration, obtained by regressing the latter on maternal smoking) on eczema over time adjusting for confounders. For the three transition periods of 1-or-2 to 4 years, 4-10, and 10-18 years, we estimated risks of persistent, incident, and remitting eczema associated with the interaction using repeated measurements.

RESULTS

If the mother smoked during gestation, longer Resid-BF-duration was associated with a lower risk of eczema, compared to if she did not smoke. The risk ratios (95% CI) if the mother smoked during gestation and exclusively breastfed for at least 3, 9, 15, 21 weeks are 0.7 (0.6, 1.7), 0.6 (0. 4, 0.9), 0.5 (0.3, 0.8), and 0.4 (0.2, 0. 8), respectively. Additionally, in all three transition periods, the risk of persistent eczema was lower with longer Resid-BF-duration if the mother smoked during gestation.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest a protective effect of gestational smoking combined with longer duration of exclusive breastfeeding on early-onset persistent eczema. Future studies should examine underlying biological mechanisms. Prolonged breastfeeding should be encouraged even if the mother smoked during gestation.

Breastfeeding and Atopic Dermatitis Risk: A Systematic Review and Meta-Analysis of Prospective Cohort Studies

OBJECTIVES

The effect of breastfeeding on atopic dermatitis (AD) remains controversial. To determine the association -between breastfeeding and AD, we conducted an updated meta-analysis of prospective cohort studies.

METHODS

A comprehensive search of PubMed, EMBASE, MEDLINE and Cochrane Library was conducted. Studies meeting the predetermined criteria were evaluated by 2 authors independently. The pooled relative risk (RR) adjusted for confounders with its 95% CI was calculated by a random-effects model. Heterogeneity was explored by subgroup analysis and meta-regression.

RESULTS

A total of 27 studies were included for meta-analysis. The pooled estimates for the effect of total and exclusive breastfeeding on AD were 1.01 (95% CI 0.93-1.10) and 0.99 (95% CI 0.88-1.11), respectively. Heterogeneity was substantial across studies (total: p < 0.01 or I2 = 65.2%; exclusive: p < 0.01 or I2 = 72.3%). There was a weak evidence for a protective effect of breastfeeding against AD in cohorts with atopic heredity (total: RR 0.85, 95% CI 0.74-0.98; exclusive: RR 0.83, 95% CI 0.70-0.97). In cohorts without atopic heredity, the effect shifted to the risk side when limited to exclusive breastfeeding (RR 1.19, 95% CI 1.02-1.40) while it dropped towards null when limited to total breastfeeding (RR 1.11, 95% CI 0.94-1.31).

CONCLUSIONS

There is no association between AD and breastfeeding, regardless of total or exclusive breastfeeding patterns. There is some evidence for a protective function of exclusive and total breastfeeding in a cohort with atopic heredity. The effect shifts to the risk side in cohorts without atopic heredity. However, these findings should be interpreted with caution because heterogeneity is evident.

Genetic, Clinical, and Environmental Factors Associated With Persistent Atopic Dermatitis in Childhood

Importance

Knowledge about factors associated with persistence of atopic dermatitis (AD) during childhood is sparse.

Objective

To explore heritable, environmental, and clinical factors associated with persistent AD based on 13 years' follow-up of an at-risk birth cohort.

Design, Setting, and Participants

In the Copenhagen Prospective Study on Asthma in Childhood 2000 (COPSAC2000) clinical birth cohort study, 411 children born to mothers with asthma were followed up until the age of 13 years at a clinical research unit in Copenhagen, Denmark, from August 1998 to June 2015. Atopic dermatitis was diagnosed prospectively during close clinical follow-up according to the criteria of Hanifin and Rajka. Data were gathered on parental history, social circumstances, and environmental factors through parent interviews. The cohort was followed up with biannual visits to the clinic until the age of 7 years and were seen again at age 13 years. Data were analyzed from August 2015 to January 2018.

Main Outcomes and Measures

Atopic dermatitis was diagnosed using Hanifin and Rajka major and minor criteria, and severity was determined by Scoring Atopic Dermatitis (SCORAD) index, with possible scores from 0 to 83, with higher scores indicating more severe AD.

Results

Of the 411 children in the cohort, 203 (49.4%) were male and 186 (45.3%) were diagnosed with AD before the age of 13 years; 40 of 166 children (24.1%) had persistent AD at the age of 13 years, and 126 (76.0%) experienced remission. Factors associated with persistent AD to age 13 years included heritability, environmental exposures, asthma and allergic sensitization, clinical presentation at the time of diagnosis, the composition of Hanifin and Rajka diagnostic minor criteria, and AD severity according to SCORAD. A higher AD genetic risk score was associated with an increased the risk for persistent AD (multivariable odds ratio [OR], 1.8; 95% CI, 1.1-2.9; P = .02), together with paternal asthma (multivariable OR, 3.7; 95% CI, 1.2-11.5; P = .02); paternal AD (multivariable OR, 6.2; 95% CI, 1.17-23.2; P = .007), and higher social circumstances (multivariable OR, 1.6; 95% CI, 1.0-2.5; P = .05). Particular clinical presentations at time of diagnosis were also associated with specific minor criteria of Hanifin and Rajka (Dennie-Morgan and anterior neck folds, white dermographism, intolerance to wool, itching when sweating, tendency to skin infection, food intolerance, and food allergy) (OR, 2.6; 95% CI, 1.1-6.2; P = .03) as well as increased severity at diagnosis (OR, 1.1; 95% CI, 1.0-1.1; P = .007).

Conclusions and Relevance

In a birth cohort of children at risk for asthma who received close clinical follow-up to age 13 years, known genetic AD risk variants, paternal asthma and AD, high social circumstances, diagnostic minor criteria, and disease severity at onset were associated with persistent AD at age 13 years. These findings may be applied in clinical practice to evaluate the likely disease course for individual patients.

Appropriate age range for introduction of complementary feeding into an infant's diet

Following a request from the European Commission, the Panel on Nutrition, Novel Foods and Food Allergens (NDA) revised its 2009 Opinion on the appropriate age for introduction of complementary feeding of infants. This age has been evaluated considering the effects on health outcomes, nutritional aspects and infant development, and depends on the individual's characteristics and development. As long as foods have an age-appropriate texture, are nutritionally appropriate and prepared following good hygiene practices, there is no convincing evidence that at any age investigated in the included studies (< 1 to < 6 months), the introduction of complementary foods (CFs) is associated with adverse health effects or benefits (except for infants at risk of iron depletion). For nutritional reasons, the majority of infants need CFs from around 6 months of age. Infants at risk of iron depletion (exclusively breastfed infants born to mothers with low iron status, or with early umbilical cord clamping (< 1 min after birth), or born preterm, or born small-for-gestational age or with high growth velocity) may benefit from earlier introduction of CFs that are a source of iron. The earliest developmental skills relevant for consuming pureed CFs can be observed between 3 and 4 months of age. Skills for consuming finger foods can be observed in some infants at 4 months, but more commonly at 5-7 months. The fact that an infant may be ready from a neurodevelopmental perspective to progress to a more diversified diet before 6 months of age does not imply that there is a need to introduce CFs. There is no reason to postpone the introduction of potentially allergenic foods (egg, cereals, fish and peanut) to a later age than that of other CFs as far as the risk of developing atopic diseases is concerned. Regarding the risk of coeliac disease, gluten can be introduced with other CFs.

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.

Associations of gestational and the first year of life exposure to ambient air pollution with childhood eczema in Hubei, China

Whether exposure to air pollution is associated with the increased incidence of childhood eczema is controversial. Only a few previous researches about the relationship between gestational and early-life exposures to ambient air pollutants and childhood eczema were conducted in China, and there is a lack of studies in Hubei province. This study aimed to explore the associations between air pollution exposure in gestation and the first year of life and childhood eczema. From November to December 2017, a total of 3383 children aged 3-6 years were recruited from 12 kindergartens in Hubei, China; 3167 were included in the final analysis. Parent-reported data involved with childhood eczema was inquired by questionnaire, and the concentrations of NO₂, PM_2.5, and PM₁₀ were acquired from air quality monitoring stations which were the nearest to the twelve kindergartens. A binary logistic regression model was used to evaluate the associations of period-mean concentrations of individual pollutant exposure with childhood eczema. Of the 3167 children, 848 (26.8%) had a history of doctor-diagnosed eczema. After adjusting for the covariates, high levels of NO₂, PM_2.5, and PM₁₀ exposures were significantly associated with a positive increase in risk of childhood eczema during the gestational period and the first year of life. In the gestational period, the estimate OR in the 3rd and 4th quartiles of NO₂ was 1.256 and 1.496, respectively. During the first year of life, the estimate OR in the 3rd and 4th quartiles of NO₂ was 1.371 and 1.335, respectively. Our study indicated that the gestational period and the first year of life exposures to high levels of ambient NO₂, PM_2.5, and PM₁₀ were significantly associated with increased eczema among preschool children. Some effective measures of prevention and intervention could be developed for preschool children.

Clinical onset of atopic eczema: Results from 2 nationally representative British birth cohorts followed through midlife

Background

Atopic eczema onset is described primarily in early childhood, and the frequency and characteristics of adult-onset disease remain controversial.

Objective

We sought to determine the proportion of subjects who report atopic eczema symptoms between birth and midadulthood and to examine demographic, immunologic, and genetic factors associated with period of symptom onset.

Methods

We conducted a longitudinal study using data from 2 nationally representative community-based birth cohorts from the United Kingdom: the British Cohort Studies 1958 and 1970. Subjects were followed from birth through age 42 to 50 years. The primary outcome was the age period of self-reported atopic eczema symptom onset based on repeated measures of self-reported atopic eczema at each survey wave.

Results

The annual period prevalence of atopic eczema ranged from 5% to 15% in 2 cohorts of more than 17,000 participants each followed from birth through middle age. There was no clear trend in prevalence by age, and among adults reporting active atopic eczema during a given year, only 38% had symptom onset reported in childhood. When compared with subjects whose eczema started in childhood, those with adult-onset disease were more likely to be women, from Scotland or Northern England, of lower childhood socioeconomic group, smokers in adulthood, and less likely to have a history of asthma. In a subanalysis using data from the 1958 cohort only, genetic mutations previously associated with atopic eczema, including filaggrin-null mutations, and allergen-specific IgE were more common among those with childhood-onset disease.

Conclusion

Rates of self-reported atopic eczema remain high after childhood, and adult-onset atopic eczema has different risk factor associations than childhood-onset eczema.

Complementary feeding and food allergy, atopic dermatitis/eczema, asthma, and allergic rhinitis: a systematic review

BACKGROUND

Nutrition during infancy and toddlerhood may influence health and disease prevention across the life span. Complementary feeding (CF) starts when human milk or infant formula is complemented by other foods and beverages, beginning during infancy and continuing to age 24 mo.

OBJECTIVES

The aim of this study was to describe systematic reviews conducted for the USDA and the Department of Health and Human Services Pregnancy and Birth to 24 Months Project to answer the following question: What is the relationship between the timing of the introduction of complementary foods and beverages (CFBs), or types and amounts of CFBs consumed, and the development of food allergy, atopic dermatitis/eczema, asthma, and allergic rhinitis?

METHODS

The literature was searched using 4 databases (CINAHL, Cochrane, Embase, PubMed) to identify articles published from January 1980 to February 2017 that met predetermined inclusion criteria. For each study, data were extracted and risk of bias was assessed. The evidence was qualitatively synthesized to develop a conclusion statement, and the strength of the evidence was graded.

RESULTS

Thirty-one included articles addressed the timing of CFB introduction, and 47 articles addressed the types and amounts of CFBs consumed.

CONCLUSIONS

Moderate evidence suggests that there is no relationship between the age at which CF first begins and the risk of developing food allergy, atopic dermatitis/eczema, or childhood asthma. Limited to strong evidence, depending on the specific food, suggests that introducing allergenic foods in the first year of life (after 4 mo) does not increase the risk of food allergy and atopic dermatitis/eczema but may prevent peanut and egg allergy. There is not enough evidence to determine a relationship between diet diversity or dietary patterns and atopic disease. Research is needed to address gaps and limitations in the evidence on CF and atopic disease, including research that uses valid and reliable diagnostic measures and accounts for key confounders and potential reverse causality.

Atopic dermatitis, educational attainment and psychological functioning: a national cohort study

BACKGROUND

Atopic dermatitis (AD) might adversely affect academic performance, possibly through influences on psychological functioning such as stress resilience.

OBJECTIVES

To investigate the association of atopic dermatitis with stress resilience, cognitive function and educational attainment.

METHODS

We used data from a national cohort of men who underwent a military conscription examination at ages 17-20 years in Sweden between 1969 and 1976. All potential conscripts met a physician who assessed current or previous history of AD. Stress resilience was measured by a psychologist using a semistructured interview. The conscription assessment included a written cognitive function test. The highest level of education achieved was identified through record linkage.

RESULTS

The study population included 234 715 men, 1673 (0·7%) of whom had a diagnosis of AD. AD was associated with a greater risk of low stress resilience [adjusted relative risk ratio (RRR) 1·60, 95% confidence interval (CI) 1·38-1·86]. AD was associated with higher cognitive function (β-coefficient 0·15, 95% CI 0·05-0·24) and higher educational level (RRR 1·29, 95% CI 1·13-1·47). However, adjustment for socioeconomic characteristics of the family of origin attenuated the magnitude of the associations and eliminated the statistical significance (β-coefficient 0·06, 95% CI -0·03 to 0·15; RRR 1·16, 95% CI 1·00-1·35).

CONCLUSIONS

Swedish men with AD had lower stress resilience in late adolescence but did not have lower cognitive function or poorer educational attainment. The lower stress resilience associated with AD is consistent with an increased risk of possible long-term adverse health outcomes.

Associations between maternal socioeconomic position and psoriasis: a cohort study among the offspring of the Danish National Birth Cohort

BACKGROUND

The socioeconomic determinants of paediatric-onset psoriasis have not been previously investigated.

OBJECTIVE

To identify whether a social gradient exists for paediatric-onset psoriasis, using measures of maternal socioeconomic position.

METHODS

Data on paediatric-onset psoriasis from 36 003 Danish National Birth Cohort offspring were cross-linked with nationwide registry data on maternal age and three measures of maternal socioeconomic position: maternal educational attainment, maternal labour market attachment and equivalized household income. Univariable and multivariable logistic regression analyses were conducted to estimate the odds ratios (ORs) of psoriasis in the offspring, in cohort analyses for data from the year of enrolment and cross-sectional analyses from the year of the 11-year follow-up.

RESULTS

Maternal age at birth, maternal educational attainment and equivalized household income were inversely associated with psoriasis in the offspring. Low maternal educational attainment was associated with offspring psoriasis [adjusted OR 1·62, 95% confidence interval (CI) 1·20-2·18] after adjusting for maternal psoriasis and age in the cohort analysis. The crude OR of psoriasis in offspring of mothers in the highest quartile compared with mothers in the lowest quartile of equivalized household income was 0·57 (95% CI 0·43-0·76), and the adjusted OR was 0·59 (95% CI 0·44-0·80) after adjusting for maternal psoriasis and age. Similar results were observed for data on maternal socioeconomic position at enrolment and at follow-up.

CONCLUSIONS

A steep social gradient in paediatric-onset psoriasis was observed. Maternal socioeconomic position may play a role in early-life exposure to modifiable risk factors for psoriasis. Future studies may help to elucidate which biological factors mediate the social gradient observed in our study.

Contrasting associations of maternal smoking and pre-pregnancy BMI with wheeze and eczema in children

BACKGROUND

Childhood allergies are dynamic and associated with environmental factors. The influence of prenatal maternal smoking and obesity on childhood allergies and their comorbidities remains unclear, especially in prospective cohorts with serial longitudinal observations.

OBJECTIVE

We examined time trends in the prevalence and comorbidity of childhood allergies, including wheeze, eczema, and rhinoconjunctivitis, using a large-scale, population-based birth cohort in Japan, and assessed the effects of prenatal maternal smoking and BMI on the risk of childhood allergies.

METHODS

Parents completed the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaires about symptoms of allergies and their risk factors at age 1, 2, 4, and 7 years. Complete data from all pre- and postnatal questionnaires at age 1, 2, 4, and 7 were available for 3296 mother-child pairs.

RESULTS

We observed significant overlap of childhood allergies at 1, 2, 4, and 7 years. Maternal serum cotinine during pregnancy was associated with increased risk of wheezing in the children at age 1, 2, and 4 but disappeared at age 7. In contrast, maternal cotinine levels were inversely associated with the prevalence of eczema in children at age 7. We additionally observed that maternal pre-pregnancy BMI, not children's BMI, had a positive association with wheeze and an inverse association with eczema in 7-year-old children, respectively. We did not find any association of examined maternal factors and rhinoconjunctivitis.

CONCLUSIONS

We demonstrated contrasting association of prenatal maternal smoking and high BMI with postnatal wheeze and eczema. For precise assessment of allergy-associated risk factors, we need to contrast risk factors for different allergic diseases since focusing solely on one allergic disease may result in misleading information on the role of different risk factors.

The association between early life antibiotic use and allergic disease in young children: recent insights and their implications

INTRODUCTION

Greater prescribing of antibiotics to infants has coincided with an epidemic of allergic disease. Through meta-analytic synthesis, accumulating evidence from prospective or database cohorts suggests a link between infant antibiotic treatment and the development of atopy. Stronger associations seen with multiple course and broad-spectrum antibiotic treatment add to biological plausibility. A major bias, confounding by indication, has been addressed in studies on antibiotic treatment of conditions which do not precede allergic disease. Areas covered: Our review provides an up-to-date synthesis of the current literature on associations between infant antibiotic exposure and future allergic disease. We discuss methods that assist in reducing study bias and look at new insights from studies of the infant gut microbiome. Expert commentary: Large-scale profiling of the gut microbiome provides a new tool for disentangling biases found in observational studies of infant antibiotic use. To date, microbial dysbiosis of the infant gut has been reported to predict allergic disease independent of antibiotic exposure up to 3 months after birth. However, these studies have not accounted for antibiotic treatment in later infancy. Continued study of the infant gut microbiome, mycobiome, or resistome will provide a closer link to antibiotic treatment or refute it as a cause of allergic disease.

Association of Infant Eczema with Childhood and Adult Asthma: Analysis of Data from the 1958 Birth Cohort Study

The influence of early life exposures on later life disease has for some time provided clues to modifiable risk factors of disease. The “atopic march” is thought to play a role in the progression of allergic diseases and may offer an opportunity to lower asthma’s health and socioeconomic burden, although evidence remains controversial. We aimed to examine the relationship between early life eczema and asthma later in life. Using the National Child Development Study, we examined infant eczema and childhood and adult asthma. Data related to asthma or wheezing bronchitis were available for 13,503 (73%; 95% CI 72–74), 11,503 (61%; 95% CI 60–61), 12,524 (68%; 95% CI 67–69), 11,194 (60%; 95% CI 60–60), 9377 (51%; 95% CI 51–51), and 9760 (53%; 95% CI 52–53) subjects at ages 11, 16, 23, 33, 44, and 50 years, respectively. Logistic regression models were fitted to examine each wave separately before and after adjusting for a range of potential confounders. Generalised estimating equation (GEE) methods were undertaken to examine the associations after pooling all data from questionnaires. The prevalence of self-reported asthma in those that had previously reported infant eczema ranged from 1.0%; 95% CI 0.9–1.4 (age 44 years) to 2.2%; 95% CI 2.1–2.3 (age 33 years). Participants with infant eczema had a 2–3-fold increased risk of reporting asthma in childhood and adulthood; this was 1.6 times at age 44 years when using spirometry measures. Similar effect sizes were observed in the GEE models when considering all participants (OR 2.9; 95% CI 2.6–3.2). Childhood and adult asthma were consistently associated with infant eczema both by using the self-reported data and lung measures.

New insights into the phenotypes of atopic dermatitis linked with allergies and asthma in children: An overview

Atopic dermatitis (AD) is a complex disease with multiple causes and complex mechanistic pathways according to age of onset, severity of the illness, ethnic modifiers, response to therapy and triggers. A group of difficult-to-manage patients characterized by early-onset AD and severe lifelong disease associated with allergic asthma and/or food allergy (FA) has been identified. In this study, we focus on these severe phenotypes, analysing their links with other atopic comorbidities, and taking into account the results from recent cohort studies and meta-analyses. The main hypothesis that is currently proposed to explain the onset of allergic diseases is an epithelial barrier defect. Thus, the atopic march could correspond to an epithelial dysfunction, self-sustained by a secondary allergenic sensitization, explaining the transition from AD to allergic asthma. Furthermore, AD severity seems to be a risk factor for associated FA. Results from population-based, birth and patient cohorts show that early-onset and severe AD, male gender, parental history of asthma, and early and multiple sensitizations are risk factors leading to the atopic march and the development of asthma. The importance of environmental factors should be recognized in these high-risk children and prevention programs adapted accordingly. Effective targeted therapies to restore both barrier function and to control inflammation are necessary; early emollient therapy is an important approach to prevent AD in high-risk children. Clinicians should also keep in mind the specific risk of atopic comorbidities in case of filaggrin loss-of-function mutations and the rare phenotypes of orphan syndromes due to heritable mutations in skin barrier components.

Atopic Dermatitis: Disease Background and Risk Factors

Multiple risk factors have been associated with the development of atopic dermatitis (AD). Recent advances in understanding the role of genetics in this disease have been made, with discovery of the filaggrin (FLG) gene as the most notable so far. In addition to FLG gene mutations as a risk factor for AD, a positive family history of atopic or allergic disease in either parent, has been shown to confer a greater risk of developing AD. Atopic dermatitis usually presents early in life and is thought to represent the initial-step in the "atopic march" which is characterized by the development of other atopic diseases later in life such as asthma, allergic rhinitis and/or rhinoconjunctivitis, food allergies and hay fever. Other comorbid diseases that have been associated with AD include increase risk of viral and bacterial skin infections, neuropsychiatric diseases such as attention-deficit hyperactivity disorders (ADHD) and autistic spectrum disorder (ASD). Patients with AD, have also been found to have worse sleep quality overall compared to patients without AD. In this chapter, we will discuss the risk factors associated with development of atopic dermatitis as well as the most commonly reported comorbidities in patients with this disease.

Pre- and Postnatal Smoking Exposure and Risk of Atopic Eczema in Young Japanese Children: A Prospective Prebirth Cohort Study

Introduction

Epidemiological evidence regarding the effect of perinatal smoking exposure on atopic eczema in children continues to be inconclusive. The aim of this prospective prebirth cohort study was to investigate the association between prenatal smoking exposure and postnatal living with household smokers and the risk of atopic eczema in Japanese children aged 23 to 29 months.

Methods

Study subjects were 1354 Japanese mother-child pairs. Information on the variables under study was obtained through questionnaires which were completed by mothers, first prior to delivery, then shortly after birth and subsequently around 4, 12, and 24 months after delivery. Eczema in the last 12 months was defined according to the criteria of the International Study of Asthma and Allergies in Childhood. Physician-diagnosed atopic eczema was considered present if reported by mothers.

Results

Compared with no perinatal smoking exposure, prenatal smoking exposure only was associated with an increased risk of physician-diagnosed atopic eczema (adjusted odds ratio = 7.11, 95% confidence interval: 1.43 to 27.8). Postnatal living with at least one household smoker only was not associated with the risk of physician-diagnosed atopic eczema; neither was the combination of both prenatal smoking exposure and postnatal living with at least one household smoker. No association was observed between perinatal smoking exposure status and the risk of eczema as defined according to the International Study of Asthma and Allergies in Childhood criteria.

Conclusions

Our findings suggest that maternal smoking during pregnancy may increase the risk of atopic eczema in young children.

Implication

In the present prebirth cohort study, we assessed the independent and additive effects of pre- and postnatal exposure to tobacco smoking on atopic eczema in children. Compared with no perinatal smoking exposure, prenatal smoking exposure only was significantly associated with an increased risk of atopic eczema. Postnatal smoking exposure only was not associated with the risk of atopic eczema; neither was the combination of both pre- and postnatal smoking exposure. This is the first epidemiological study to show a positive association between prenatal smoking exposure only and the risk of atopic eczema.

Association between breastfeeding and eczema during childhood and adolescence: A cohort study

Background

Breastfeeding is said to protect children from eczema (atopic dermatitis), but the available evidence is conflicting and subject to the influences of parental atopy and reverse causation (when mothers extended duration of breastfeeding because their children had eczema).

Methods

In the prospective, population-based Leicester Respiratory Cohort study, we assessed duration of breastfeeding in children aged 1–4 years. Prevalence of eczema was determined by questionnaire surveys that were repeated until the children were 17 years old. We investigated the association between having been breastfed and current eczema using generalized estimating equations, adjusting for potential confounders, and tested for effect modification by parental atopy. We also assessed the association between having been breastfed and incident eczema at ages 2, 4, and 6 years using multivariable logistic regression.

Results

Among the 5,676 children in the study, 2,284 (40%) had never been breastfed, while 1,610 (28%), 705 (12%), and 1,077 (19%) had been breastfed for 0–3, 4–6, and >6 months, respectively. Prevalence of current eczema decreased from 36% in 1-year-olds to 18% in children aged 10–17 years. Breastfeeding was not associated with current eczema. Compared with children who had never been breastfed, the adjusted odds ratios for current eczema at any age were 1.02 (95% confidence interval 0.90–1.15) for children who had been breastfed for 0–3 months, 0.97 (0.82–1.13) for children breastfed for 4–6 months, and 0.98 (0.85–1.14) for children breastfed for >6 months. There was no strong evidence for an effect modification by parental atopy (p-value for interaction term was 0.061) and no association between having been breastfed and incident eczema later in childhood.

Conclusions

This population-based cohort study found no evidence for protection of breastfeeding against childhood eczema at any age, from infancy through adolescence.

Human Milk and Allergic Diseases: An Unsolved Puzzle

There is conflicting evidence on the protective role of breastfeeding in relation to the development of allergic sensitisation and allergic disease. Studies vary in methodology and definition of outcomes, which lead to considerable heterogeneity. Human milk composition varies both within and between individuals, which may partially explain conflicting data. It is known that human milk composition is very complex and contains variable levels of immune active molecules, oligosaccharides, metabolites, vitamins and other nutrients and microbial content. Existing evidence suggests that modulation of human breast milk composition has potential for preventing allergic diseases in early life. In this review, we discuss associations between breastfeeding/human milk composition and allergy development.

Public Health Burden and Epidemiology of Atopic Dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disorder with significant morbidity and quality-of-life impairment. The epidemiology of AD is complex and challenging to study. The 1-year US prevalence of AD was 12.98% in children in 2007-2008 and 7.2%-10.2% in adults in 2010-2012. There is considerable statewide and countrywide variation of AD prevalence and severity. The prevalence of childhood AD dramatically increased over the past few decades but may be leveling off in developed nations. AD is associated with increased direct and indirect costs to payers and patients, thereby contributing toward a considerable public health burden.

Atopic Eczema: Genetic Associations and Potential Links to Developmental Exposures

Atopic eczema (AE), or atopic dermatitis (AD), is a common inflammatory skin disease with a disrupted epidermal barrier and an allergic immune response. AD/AE is prominently characterized by a symptomatic itch and transient skin lesions. Infants compose a significant percentage affected. Two models have been proposed to explain AD/AE skin pathology: the gut microbiome-focused inside-outside model and the outside-inside model concentrating on the disrupted skin barrier/skin microbiome. Gene disruptions contributing to epidermal structure, as well as those in immune system genes, are implicated. Over 30 genes have been linked to AD/AE with Flg and Tmem79/Matt alterations being common. Other linked disruptions are in the interleukin-1 family of cytokines/receptors and the TH2 gene family of cytokines. Inheritable epigenetic modifications of the genes or associated proteins may also be involved. Skin barrier disruption and the allergic immune response have been the main foci in mechanistic studies of AD/AE, but the role of the environment is becoming more apparent. Thus, an examination of in utero exposures could be very helpful in understanding the heterogeneity of AD/AE. Although research is limited, there is evidence that developmental exposure to environmental tobacco smoke or phthalates may impact disease. Management for AD/AE includes topical corticosteroids and calcineurin inhibitors, which safely facilitate improvements in select individuals. Disease heterogeneity warrants continued research not only into elucidating disease mechanism(s), via identification of contributing genetic alterations, but also research to understand how/when these genetic alterations occur. This may lead to the cure that those affected by AD/AE eagerly await.

Household environment, lifestyle behaviors, and dietary habits in relation to childhood atopic eczema in Shanghai, China

PURPOSES

We aim to investigate associations of the child's individual characteristics, building characteristics, home environmental exposures, family lifestyle behaviors, and dietary habits on childhood eczema during lifetime-ever and in the last year before the survey.

METHODS

During April 2011-April 2012, we conducted a cross-sectional study and collected 13,335 parents-reported questionnaires of 4-6-year-old children from 72 kindergartens in Shanghai, China. Logistic regression model was used to investigate associations.

RESULTS

After adjusted for sex, age, family history of atopy, and questionnaire reporter, the factors which were strongly associated (increased odds >30% and p value <0.05) with lifetime-ever eczema included mother employed during pregnancy (adjusted OR 1.33), residence renovated during pregnancy (1.49) and in the child's first year of life (1.31), using laminate (1.58) and solid (1.42) wood as material of floor covering (compared to using cement), residence located in urban district (1.38), and dampness-related exposures in the early residence (mold spots/stains: 1.41; mold odor: 1.41) and in the current residence (water damage: 1.33; damp stains: 1.34; mold spots: 1.32; and windows pane condensation: 1.31). Parental smoking, pet-keeping, and incense-burning had no significant associations with childhood eczema. Similar associations were found for eczema in the last year before the survey. Families with sick children likely changed lifestyle behaviors and dietary habits.

CONCLUSIONS

Childhood eczema could be influenced by many household environmental and non-environmental factors. Exposures during early lifetime likely have greater impact on childhood eczema than current exposures. Associations of lifestyle behaviors and dietary habits with childhood eczema could be modified by family avoidance behaviors.

Tobacco smoking and breastfeeding: Effect on the lactation process, breast milk composition and infant development. A critical review

Approximately 10% of women report smoking during pregnancy. The number of breastfeeding women who relapse back to smoking is even greater. Smoking may cause adverse changes to the milk's composition by not only reducing its protective properties, but also by affecting the infant's health. The pathophysiological mechanisms underlying these adverse effects are not entirely known. This article is a review of previous reports about the effects of smoking on the lactation process, breast milk composition and infant development. A systematic search for English language articles published until 2015 was made, using a MEDLINE data. The key search terms were "smoking and breastfeeding", "smoking and lactation", "smoking and milk composition", "nicotine and breast milk". Studies have shown that nicotine levels in breast milk of women who smoke are three times higher than those in the plasma levels. Breast milk volume is reduced and the duration of lactation period is shorter. Smoking causes adverse changes to the milk's composition by not only reducing its protective properties, but also affecting infants' response to breastfeeding and to breast milk.

Association between domestic water hardness, chlorine, and atopic dermatitis risk in early life: A population-based cross-sectional study

BACKGROUND

Domestic water hardness and chlorine have been suggested as important risk factors for atopic dermatitis (AD).

OBJECTIVE

We sought to examine the link between domestic water calcium carbonate (CaCO3) and chlorine concentrations, skin barrier dysfunction (increased transepidermal water loss), and AD in infancy.

METHODS

We recruited 1303 three-month-old infants from the general population and gathered data on domestic water CaCO3 (in milligrams per liter) and chlorine (Cl2; in milligrams per liter) concentrations from local water suppliers. At enrollment, infants were examined for AD and screened for filaggrin (FLG) skin barrier gene mutation status. Transepidermal water loss was measured on unaffected forearm skin.

RESULTS

CaCO3 and chlorine levels were strongly correlated. A hybrid variable of greater than and less than median levels of CaCO3 and total chlorine was constructed: a baseline group of low CaCO3/low total chlorine (CaL/ClL), high CaCO3/low total chlorine (CaH/ClL), low CaCO3/high total chlorine (CaL/ClH) and high CaCO3/high total chlorine (CaH/ClH). Visible AD was more common in all 3 groups versus the baseline group: adjusted odds ratio (AOR) of 1.87 (95% CI, 1.25-2.80; P = .002) for the CaH/ClL group, AOR of 1.46 (95% CI, 0.97-2.21; P = .07) for the CaL/ClH, and AOR of 1.61 (95% CI, 1.09-2.38; P = .02) for the CaH/ClH group. The effect estimates were greater in children carrying FLG mutations, but formal interaction testing between water quality groups and filaggrin status was not statistically significant.

CONCLUSIONS

High domestic water CaCO3 levels are associated with an increased risk of AD in infancy. The influence of increased total chlorine levels remains uncertain. An intervention trial is required to see whether installation of a domestic device to decrease CaCO3 levels around the time of birth can reduce this risk.