What's new in atopic eczema? An analysis of systematic reviews published in 2014. Part 1. Epidemiology, risk factors and outcomes

Low vitamin D during pregnancy is associated with infantile eczema by up-regulation of PI3K/AKT/mTOR signaling pathway and affecting FOXP3 expression: A bidirectional cohort study

Vitamin D has received increasing attention because of its association with atopic disease development. Limited studies that have been done on the impact of maternal vitamin D levels during pregnancy on infantile eczema are still debatable. We wanted to discover the effect of maternal vitamin D on infantile eczema and explore whether regulatory T cells (Treg) play a role in this process. 219 pairs of mothers and children were enrolled. Maternal fasting venous blood was collected in pregnancy's second and third trimesters to determine vitamin D levels. Cord blood and placenta samples were collected during childbirth for detecting levels of genes, proteins and cytokines. Pediatricians followed up the prevalence of eczema in infants within 1 year. The reported rate of vitamin D deficiency and insufficiency was 35.6% and 28.3%. Lower maternal 25(OH)D3 levels were related to a higher risk of infantile eczema. Foxp3 gene expression is lower in cord blood of infants with eczema compared to infants without eczema. There was a positive correlation between maternal 25(OH)D3 levels and the expression of FOXP3 gene in cord blood. Compared to vitamin D sufficiency women, vitamin D deficiency women's placental FOXP3 protein expression was decreased and PI3K/AKT/mTOR protein was up-regulated. Our study demonstrates that low prenatal maternal vitamin D levels increased the risk of infantile eczema aged 0-1 year, which might be related to the downregulating of the FOXP3 gene expression in cord blood and decreased placental FOXP3 protein expression. Low placental FOXP3 protein was related with activating PI3K/AKT/mTOR signaling pathway.

Long-term impact of pre-incision antibiotics on children born by caesarean section: a longitudinal study based on UK electronic health records

BACKGROUND

Since changes in the national guidance in 2011, prophylactic antibiotics for women undergoing caesarean section are recommended prior to skin incision, rather than after the baby's umbilical cord has been clamped. Evidence from randomised controlled trials conducted outside the UK has shown that this reduces maternal infectious morbidity; however, the prophylactic antibiotics also cross the placenta, meaning that babies are exposed to them around the time of birth. Antibiotics are known to affect the gut microbiota of the babies, but the long-term effects of exposure to high-dose broad-spectrum antibiotics around the time of birth on allergy and immune-related diseases are unknown.

OBJECTIVES

We aimed to examine whether or not in-utero exposure to antibiotics immediately prior to birth compared with no pre-incisional antibiotic exposure increases the risk of (1) asthma and (2) eczema in children born by caesarean section.

DESIGN

This was a controlled interrupted time series study.

SETTING

The study took place in primary and secondary care.

PARTICIPANTS

Children born in the UK during 2006-18 delivered by caesarean section were compared with a control cohort delivered vaginally.

INTERVENTIONS

In-utero exposure to antibiotics immediately prior to birth.

MAIN OUTCOME MEASURES

Asthma and eczema in children in the first 5 years of life. Additional secondary outcomes, including other allergy-related conditions, autoimmune diseases, infections, other immune system-related diseases and neurodevelopmental conditions, were also assessed.

DATA SOURCES

The Health Improvement Network (THIN) and the Clinical Practice Research Datalink (CPRD) primary care databases and the Hospital Episode Statistics (HES) database. Previously published linkage strategies were adapted to link anonymised data on mothers and babies in these databases. Duplicate practices contributing to both THIN and the CPRD databases were removed to create a THIN-CPRD data set.

RESULTS

In the THIN-CPRD and HES data sets, records of 515,945 and 3,945,351 mother-baby pairs were analysed, respectively. The risk of asthma was not significantly higher in children born by caesarean section exposed to pre-incision antibiotics than in children whose mothers received post-cord clamping antibiotics, with an incidence rate ratio of 0.91 (95% confidence interval 0.78 to 1.05) for diagnosis of asthma in primary care and an incidence rate ratio of 1.05 (95% confidence interval 0.99 to 1.11) for asthma resulting in a hospital admission. We also did not find an increased risk of eczema, with an incidence rate ratio of 0.98 (95% confidence interval 0.94 to1.03) and an incidence rate ratio of 0.96 (95% confidence interval 0.71 to 1.29) for diagnosis in primary care and hospital admissions, respectively.

LIMITATIONS

It was not possible to ascertain the exposure to pre-incision antibiotics at an individual level. The maximum follow-up of children was 5 years.

CONCLUSIONS

There was no evidence that the policy change from post-cord clamping to pre-incision prophylactic antibiotics for caesarean sections during 2006-18 had an impact on the incidence of asthma and eczema in early childhood in the UK.

FUTURE WORK

There is a need for further research to investigate if pre-incision antibiotics have any impact on developing asthma and other allergy and immune-related conditions in older children.

STUDY REGISTRATION

This study is registered as researchregistry3736.

FUNDING

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 30. See the NIHR Journals Library website for further project information.

Evidence-based management of eczema: five things that should be done more and five things that should be dropped

PURPOSE OF REVIEW

We provide readers with an evidence-informed opinion on current treatments for eczema (atopic dermatitis) with the intention of improving patient care. We suggest five treatment aspects that should be promoted and five that should be demoted. Evidence sources include key randomized controlled trials and systematic reviews.

RECENT FINDINGS

Under-treatment of eczema can be countered by more aggressive use of topical therapies including the 'get control then keep control' regimen, and systemics for severe disease, supplemented with good patient education. Topical corticosteroids should be used once daily rather than twice daily. Topical calcineurin inhibitors are useful for sensitive sites. There is little evidence to support the continued use of oral antihistamines, oral or topical antistaphylococcal treatments for infected eczema or probiotics for treating eczema. Nonpharmacological treatments including silk clothing, ion-exchange water softeners and emollient bath additives have not been shown to benefit eczema patients. Despite promising pilot studies, large trials suggest that emollients from birth do not prevent eczema and may result in harms such as increased skin infections and food allergy.

SUMMARY

New evidence-based insights on existing and newer treatments allow clinicians the opportunity to change their practice in a way that enhances patients' quality of life.

Early-life exposure to air pollution and childhood allergic diseases: an update on the link and its implications

INTRODUCTION

Although mounting evidence has linked environmental factors with childhood allergies, some specific key issues still remain unclear: what is the main environmental factor? what is the critical timing window? And whether these contribute to the development of disease?

AREAS COVERED

This selective review summarizes recent epidemiological studies on the association between early-life exposure to indoor/outdoor air pollution and childhood allergic diseases. A literature search was conducted in the PubMed and Web of Science for peer-reviewed articles published until April 2020. Exposure to the traffic-related air pollutant, NO₂, exposure during pregnancy and early postnatal periods is found to be associated with childhood allergies, and exposure during different trimesters causes different allergic diseases. However, exposure to classical air pollutants (PM₁₀ and SO₂) also contributes to childhood allergy in developing countries. In addition, early-life exposure to indoor renovation and mold/dampness significantly increases the risk of allergy in children. A synergistic effect between indoor and outdoor air pollution is found in the development of allergic diseases.

EXPERT OPINION

Early-life exposure to outdoor air pollution and indoor environmental factors plays an important role in the development of childhood allergic diseases, and the synergy between indoor and outdoor exposures increases allergy risk. The available findings support the hypothesis of the 'fetal origins of childhood allergy,' with new implications for the effective control and early prevention of childhood allergies.

Season of birth is associated with increased risk of atopic dermatitis in Japanese infants: a retrospective cohort study

Background

Several epidemiological studies have examined the possibility of a relationship between season of birth and atopic dermatitis (AD) and food allergy (FA), yet their results are contradictory. We investigated the association between season of birth and risk of AD and FA in Japanese infants.

Methods

Study subjects were 612 newborn infants born at a single obstetric/pediatric clinic without perinatal diseases. Season of birth was classified as spring (March-May), summer (June-August), autumn (September-November) or winter (December-February). AD was diagnosed according to the United Kingdom Working Party's criteria. FA was defined as present if there was a history of immediate allergic symptoms within 2 h after ingestion of a food. Specific IgE to the corresponding food was also assessed to support the diagnosis. We assessed the association between season of birth and risk of AD and FA using Cox proportional hazard models.

Results

We identified a total of 365 cases of AD occurring during 3659 person-months of follow-up. Compared with summer birth, autumn, winter, and spring birth were significantly positively associated with the risk of AD: adjusted HRs (95% CIs) were 2.67 (1.96-3.63), 1.42 (1.03-1.95), and 1.43 (1.04-1.98), respectively. We identified a total of 23 cases of physician-diagnosed FA occurring during 6815 person-months of follow-up.

Conclusions

Being born in the summer is associated with a lower risk of AD compared to other seasons of birth. The low incidence of FA in our cohort group made it difficult to establish a valid association between FA and season of birth as the statistical power was low.

What's new in atopic eczema? An analysis of systematic reviews published in 2015. Part 1: epidemiology and methodology

This review forms part of a series of annual updates that summarize the evidence base for atopic eczema (AE), providing a succinct guide for clinicians and patients. It provides a summary of key findings from 15 systematic reviews that were published during 2015, and focuses on the epidemiology and methodology issues of AE. For systematic reviews on the prevention and treatment of AE, see Part 2 of this update. The worldwide prevalence of AE during childhood has been calculated to be 7.89% (95% CI 7.88-7.89), based on studies of 1 430 329 children from 102 countries. Children with AE are four times more likely than controls to have allergic rhinitis and asthma [relative risk (RR) = 4.24, 95% CI 3.75-4.79]. Twin studies show the heritability of AE to be about 75%. AE is more prevalent in patients with vitiligo and alopecia, and is positively associated with a high body mass index in America and Asia but not in Europe. Possible relationships between AE and exercise, maternal folate supplementation, maternal stress and autism spectrum disorder (ASD) have been assessed, but more high-quality studies are needed for definitive conclusions. The Harmonising Outcomes Measures for Eczema (HOME) Initiative is developing a core set of outcome measures for AE trials. Suitable instruments for measuring quality of life are yet to be agreed, and use of Investigator Global Assessment in trials requires standardization. Transparent reporting of AE trials remains problematic.

Quality assessment of atopic dermatitis clinical practice guidelines in ≤ 18 years

Atopic dermatitis (AD) is a chronic inflammatory skin disease that affects the patients' quality of life greatly often from a very young age. Its worldwide incidence in children and adults varies, but it is usually among the first ten causes of dermatological consultation worldwide. There is a wide variety of treatment options for this condition including topical and systemic regimes. The decision to choose a treatment option in dermatological diseases is greatly influenced by the personal experience of each specialist, which increases variability in the selection of available therapies. Clinical practice guidelines (CPGs) not only offer recommendations supported on the available scientific evidence, but also are intended to assist in making appropriate decisions in clinical scenarios. To standardize the way in which CPGs should be developed, an instrument called AGREE II (Appraisal of Guidelines for Research and Evaluation) is used. In this study, ten clinical practice guidelines in ≤ 18 years were evaluated. Six domains (scope and purpose, stakeholder involvement, rigor of development, clarity and presentation, applicability, and editorial independence) were assessed for each guideline, by three reviewers. Most of the domains obtained high scores except in the applicability domain. It is suggested that future atopic dermatitis CPGs should emphasize in the facilitating factors and barriers that may influence the application of guideline recommendations.

Association between Exposure to Traffic-Related Air Pollution and Prevalence of Allergic Diseases in Children, Seoul, Korea

Although there has been suggestive evidence of the association between TRAP and ADs, findings remained inconsistent possibly due to limited population. We investigated the association between TRAP and ADs in a large population of children with rich spatial coverage and expanded age span in Seoul, Korea. TRAP exposures were estimated by categorized proximity to the nearest major road (≤150, 150–300, 300–500, and >500 m) and density of major roads within 300 meters from children's residences. We estimated the association between two TRAP exposures and three ADs using generalized mixed model after adjusting for individual characteristics. We also investigated whether the association varied by household and regional socioeconomic status. We found associations of atopic eczema with road density [OR = 1.08; 95% CI = 1.01–1.15] and road proximity [1.15, 1.01–1.32; 1.17, 1.03–1.34; and 1.16, 1.01–1.34 for ≤150, 150–300, and 300–500 m, resp., compared to >500 m]. There was no association with asthma and allergic rhinitis. Effect estimates were generally the highest in the low socioeconomic region. Children living in areas surrounded by large and busy roads were likely to be at greater risks for atopic eczema, with increased vulnerability when living in deprived areas.