Caesarean delivery and the risk of atopic dermatitis in children

Cesarean section induced dysbiosis promotes type 2 immunity but not oxazolone-induced dermatitis in mice

Delivery by cesarean section (CS) is associated with an altered gut microbiota (GM) colonization and a higher risk of later chronic inflammatory diseases. Studies investigating the association between CS and atopic dermatitis (AD) are contradictive and often biased by confounding factors. The aim of this study was therefore to provide experimental evidence for the association between CS and AD in a mouse model and clarify the role of the GM changes associated with CS. It was hypothesized that CS-delivered mice, and human CS-GM transplanted mice develop severe dermatitis due to early dysbiosis. BALB/c mice delivered by CS or vaginally (VD) as well as BALB/c mice transplanted with GM from CS or VD human donors were challenged with oxazolone on the ear. The severity of dermatitis was evaluated by ear thickness and clinical and histopathological assessment which were similar between all groups. The immune response was assessed by serum IgE concentration, local cytokine response, and presence of immune cells in the draining lymph node. Both CS-delivered mice and mice inoculated with human CS-GM had a higher IgE concentration. A higher proportion of Th2 cells were also found in the CS-GM inoculated mice, but no differences were seen in the cytokine levels in the affected ears. In support of the experimental findings, a human cohort analysis from where the GM samples were obtained found that delivery mode did not affect the children's risk of developing AD. In conclusion, CS-GM enhanced a Th2 biased immune response, but had no effect on oxazolone-induced dermatitis in mice.

Shotgun metagenomic sequencing on skin microbiome indicates dysbiosis exists prior to the onset of atopic dermatitis

BACKGROUND

While the microbiome is increasingly seen as a targetable contributor to atopic dermatitis (AD), questions remain as to whether the dysbiosis is secondary to diseased skin or if it predates symptom onset. Previous work has evaluated how the skin microbiome changes with age and established the influence of factors like delivery mode and breastfeeding on global microbiome diversity. However, these studies were unable to identify taxa which predict subsequent AD.

METHODS

Skin swab samples were collected from the first week of life for 72 children in the neonatal intensive care unit (NICU) at a single site hospital. Participants were followed for 3 years to determine their health status. We applied shotgun metagenomic sequencing to assess the microbiome differences between 31 children who went on to develop AD and 41 controls.

RESULTS

We identified that subsequent development of AD was associated with differential abundance of several bacterial and fungal taxa as well as several metabolic pathways, each of which have been previously associated with active AD.

CONCLUSIONS

Our work provides evidence of reproducibility for the previously reported dysbiotic signatures predating AD onset while also expanding prior findings through the first use of metagenomic assessment prior to AD onset. While extrapolation of our findings beyond the pre-term, NICU cohort is limited, our findings add to the evidence that the dysbiosis associated with AD pre-dates disease onset rather than reflect a secondary consequence of skin inflammation.

Birth mode is associated with development of atopic dermatitis in infancy and early childhood

Background

Birth by caesarean section (CS) is associated with development of allergic diseases, but its role in the development of atopic dermatitis (AD) is less convincing.

Objective

Our primary aim was to determine if birth mode was associated with AD in 3-year-olds and secondarily to determine if birth mode was associated with early onset and/or persistent AD in the first 3 years of life.

Methods

We included 2129 mother-child pairs from the Scandinavian population-based prospective PreventADALL cohort with information on birth mode including vaginal birth, either traditional (81.3%) or in water (4.0%), and CS before (6.3%) and after (8.5%) onset of labor. We defined early onset AD as eczema at 3 months and AD diagnosis by 3 years of age. Persistent AD was defined as eczema both in the first year and at 3 years of age, together with an AD diagnosis by 3 years of age.

Results

AD was diagnosed at 3, 6, 12, 24, and/or 36 months in 531 children (25%). Compared to vaginal delivery, CS was overall associated with increased odds of AD by 3 years of age, with adjusted odds ratio (95% confidence interval) of 1.33 (1.02-1.74), and higher odds of early onset AD (1.63, 1.06-2.48). The highest odds for early onset AD were observed in infants born by CS after onset of labor (1.83, 1.09-3.07). Birth mode was not associated with persistent AD.

Conclusion

CS was associated with increased odds of AD by 3 years of age, particularly in infants presenting with eczema at 3 months of age.

A cohort study of intrapartum group B streptococcus prophylaxis on atopic dermatitis in 2-year-old children

OBJECTIVE

To understand the occurrence of atopic dermatitis (AD) in children aged 2 years on exposure to maternal group B streptococcus (GBS) antibiotic prophylaxis (IAP).

DESIGN

Retrospective cohort study of 2909 mother-child pairs.

SETTING

Taixing People's Hospital in Eastern China.

PARTICIPANTS

Term infants born 2018-2019, followed longitudinally from birth to 2 years.

EXPOSURES

The GBS-IAP was defined as therapy with intravenous penicillin G or ampicillin or cefazolin ≥ 4 h prior to delivery to the mother. Reference infants were defined as born without or with other intrapartum antibiotic exposure.

OUTCOMES

The logistic regression models were employed to analyze the effect of intrapartum GBS prophylaxis on AD in 2-year-old children during delivery. Analysis was a priori stratified according to the mode of delivery and adjusted for relevant covariates.

RESULTS

The cohorts showed that preventive GBS-IAP was potentially associated with increased incidence of AD in children delivered vaginally according to logistic regression models before and after covariate-adjusted treatment (OR: 6.719,95% CI: 4.730-9.544,P < 0.001;aOR: 6.562,95% CI: 4.302-10.008, P < 0.001).

CONCLUSION

Prophylactic treatment of intrapartum GBS may raise the risk of AD in vaginally delivered children. These findings highlight the need to better understand the risk between childhood AD and current GBS-IAP intervention strategies.

The Role of Early Life Microbiota Composition in the Development of Allergic Diseases

Allergic diseases are becoming a major healthcare issue in many developed nations, where living environment and lifestyle are most predominantly distinct. Such differences include urbanized, industrialized living environments, overused hygiene products, antibiotics, stationary lifestyle, and fast-food-based diets, which tend to reduce microbial diversity and lead to impaired immune protection, which further increase the development of allergic diseases. At the same time, studies have also shown that modulating a microbiocidal community can ameliorate allergic symptoms. Therefore, in this paper, we aimed to review recent findings on the potential role of human microbiota in the gastrointestinal tract, surface of skin, and respiratory tract in the development of allergic diseases. Furthermore, we addressed a potential therapeutic or even preventive strategy for such allergic diseases by modulating human microbial composition.

Prevalence of eczema between cesarean-born and vaginal-born infants within 1 year of age: a systematic review and meta-analysis

This study aims to quantify the difference in prevalence of eczema between cesarean-born and vaginal-born infants within 1 year of age through a systematic review and meta-analysis. Six electronic databases were searched from inception to August 31, 2021. Studies were included if they reported the prevalence of eczema in infants within 1 year of age with specified mode of delivery. The quality of included studies was assessed using the Joanna Briggs Instrument Critical Appraisal Checklist. Pooled prevalence and odds ratio (OR) were estimated by meta-analyses of included studies. Meta-regression was conducted to explore factors affecting heterogeneity of the prevalence of eczema. Nine studies were included with 3,758 cesarean-born infants and 9,631 vaginal-born infants. The prevalence of eczema in cesarean-born infants [27.8%; 95% confidence interval (CI): 17.7-39.2] was higher than in vaginal-born infants (20.1%; 95% CI: 13.9-28.1), with a pooled OR of 1.31 (95% CI: 1.04-1.65). Subgroup analyses showed that the prevalence of eczema in cesarean-born infants varied according to country, study design, and method of ascertainment. Additionally, the pooled prevalence of eczema in vaginal-born infants differed by age at which eczema was identified. Meta-regression analysis showed that study design and eczema ascertainment method were significant sources of heterogeneity.

CONCLUSION

About 28% of cesarean-born infants within 1 year of age developed eczema, significantly higher than the 20% rate or occurrence seen in vaginal-born infants.

PROTOCOL REGISTRATION

CRD 42,020,152,437.

WHAT IS KNOWN

• Eczema, a complex inflammatory cutaneous disorder characterized by immune mediated inflammation and epidermal barrier dysfunction, is one of the most common allergic disorders in infants. • Eczema may increase the risk of immune-mediated inflammatory disease such as food allergy, asthma, and allergic rhinitis, leading to psychological and social burdens on affected individuals and their families. • Mode of delivery may be associated with the risk of developing eczema, although further studies are needed to clarify such differences.

WHAT IS NEW

• This is the first systematic review designed to estimate the prevalence of eczema in cesarean- and vaginal-born infants within 1 year of age. • Cesarean delivery may increase the risk of developing eczema in infants within the first year of life.

Developments in the field of allergy in 2020 through the eyes of Clinical and Experimental Allergy

While 2020 will be remembered for the global coronavirus pandemic, there were also important advances in the field of allergy. In this review article, we summarize key findings reported in Clinical and Experimental Allergy during 2020. We hope this provides readers with an accessible snapshot of the work published in our journal during this time.

Determinant factors of recurrence atopic dermatitis symptoms in children: A cross-sectional study

Background

Atopic dermatitis (AD) is a common health problem found in children. Understanding of the determinants of AD-related factors includes gender, family history, childbirth history, and exclusive breastfeeding.

Objective

Analyzing gender, family history, childbirth history, and exclusive breastfeeding on recurrence of AD symptoms in children.

Methods

This study employed a cross-sectional design with a purposive sampling method. The procedure for collecting data in this study included data on participant recurrence, gender, family history of atopy disease, childbirth history, and exclusive breastfeeding. The analysis used Chi-square and eta correlation test with p < 0.05.

Results

The results showed that 56.0% of male participants experienced recurrent atopic dermatitis symptoms and 56.7% of female participants did not experience recurrence (OR = 1.664; p = 0.349). It was reported that 61.3% of participants did not experience recurrent atopic symptoms with a family history of 1 atopic person and 71.4% of participants experienced recurrence with 2 atopic families (F = 2114; p = 0.349). Most participants who were delivered through cesarean delivery did not experience recurrent atopic dermatitis symptoms as much as 56.0%, while participants who had a history of spontaneous delivery mostly experienced recurrent atopic dermatitis symptoms as much as 52.9% (OR = 1.500; p = 0.467). There was a significant association between participants who received exclusive breastfeeding and recurrent atopic dermatitis symptoms (OR = 4.444; p = 0.032).

Conclusion

Recurrent of AD is influenced by exclusive breastfeeding and not influenced by gender, family history of atopy disease, and history of childbirth.

•

No significant association of gender, family history, and childbirth on recurrence of atopic dermatitis symptoms.

•

There is a significant association between exclusive breastfeeding and recurrent atopic dermatitis.

•

Participants who experience atopic dermatitis as much as 57.1% consume exclusive breastfeeding.

Prepregnancy BMI, gestational weight gain and risk of childhood atopic dermatitis: A systematic review and meta-analysis

BACKGROUND

Maternal weight before and during pregnancy influences the health of offspring. Several observational studies have investigated a link between the risk of childhood atopic dermatitis (AD) and prepregnancy maternal body mass index (BMI) and gestational weight gain (GWG), but the conclusions of these studies were inconsistent. The aim of this review was to evaluate the association between the risk of childhood AD and prepregnancy maternal BMI and GWG.

METHODS

The PubMed, Embase, Cochrane, Web of Science, and Scopus databases were searched from inception to February 2, 2021. Observational studies investigating the association between the risk of childhood AD and prepregnancy maternal BMI and GWG were included. Fixed- or random-effects models with inverse variance weights were used to calculate pooled risk estimates. Subgroup analysis and sensitivity analysis were used to explore the sources of heterogeneity.

RESULTS

Thirteen studies with a total of 114 485 participants were included. Ten studies reported prepregnancy maternal BMI, and five reported GWG. Maternal underweight was associated with a higher risk of childhood AD (odds ratio [OR] = 1.06; 95% confidence interval [CI], 1.02-1.10). Continuous BMI was not related to childhood AD (OR = 1.00; 95% CI, 0.98-1.02). In comparison with normal GWG, moderate/very high GWG increased the risk of childhood AD (OR = 1.05; 95% CI, 1.02-1.08; OR = 1.13; 95% CI, 1.07-1.19, respectively), while low GWG decreased the risk (OR = 0.92; 95% CI, 0.89-0.96). Excessive GWG relative to recommendations was associated with a higher risk of childhood AD (OR = 1.05; 95% CI, 1.01-1.10), while a lower risk of childhood AD was associated with inadequate GWG relative to recommendations (OR = 0.87, 95% CI: 0.83-0.91).

CONCLUSIONS

Maternal underweight, high GWG, and excessive GWG relative to recommendations are associated with an elevated risk of childhood AD, while low GWG and inadequate GWG relative to recommendations decreased the risk. Weight management before and during pregnancy is encouraged for primary prevention of childhood AD.

Neonatal Immune System Ontogeny: The Role of Maternal Microbiota and Associated Factors. How Might the Non-Human Primate Model Enlighten the Path?

Interactions between the immune system and the microbiome play a crucial role on the human health. These interactions start in the prenatal period and are critical for the maturation of the immune system in newborns and infants. Several factors influence the composition of the infant's microbiota and subsequently the development of the immune system. They include maternal infection, antibiotic treatment, environmental exposure, mode of delivery, breastfeeding, and food introduction. In this review, we focus on the ontogeny of the immune system and its association to microbial colonization from conception to food diversification. In this context, we give an overview of the mother-fetus interactions during pregnancy, the impact of the time of birth and the mode of delivery, the neonate gastrointestinal colonization and the role of breastfeeding, weaning, and food diversification. We further review the impact of the vaccination on the infant's microbiota and the reciprocal case. Finally, we discuss several potential therapeutic interventions that might help to improve the newborn and infant's health and their responses to vaccination. Throughout the review, we underline the main scientific questions that are left to be answered and how the non-human primate model could help enlighten the path.

The Role of Environmental Exposures in Atopic Dermatitis

PURPOSE OF REVIEW

Although genetic factors clearly play a role in the development of atopic dermatitis (AD), the recent dramatic increase in the prevalence of AD in low- and middle-income countries is not consistent with only a role of genetic factors. These findings strongly suggest that environmental factors may play an important role in the pathogenesis of AD.

RECENT FINDINGS

We reviewed the role of gene-environment studies; in utero exposures including tobacco smoke, alcohol, maternal stress, various digestive supplements, and gestational diabetes; early-life exposures including diet, gut microbiota, antibiotics, and breastfeeding; climate including temperature, ultraviolet radiation exposure, and air pollution; and household products, indoor allergens, water hardness, pH, and skin microbiota and their effects on AD. Environmental factors definitely play a role in the pathogenesis of AD. However, identifying definitive factors continues to be difficult in the setting of conflicting evidence and the complex interactions between genotypes and the environment resulting in a multitude of AD phenotypes. All of the different environmental interactions discussed highlight the importance of intervening on multiple levels in a patient's environment to improve or even prevent AD symptoms. Further, the importance of modifying environmental factors early on in a person's life is demonstrated. When possible, all of these environmental factors should be considered in treating a patient with AD and the appropriate modifications should be made at population and individual levels.