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

Patterns of Common Dermatological Conditions among Children and Adolescents in Pakistan

Background and Objectives: Dermatological disorders are highly prevalent among children in Pakistan. The present cross-sectional study aims to identify the spectrum of dermatological conditions among children and adolescents in Pakistan. Materials and Methods: A total of 582 patients (50.9% males; 49.1% females) were included in the study based on their age (5.7 ± 4.1 years), dermatological condition, and epidemiology. The youngest patient was aged ten days, whereas the eldest was seventeen. Age criteria were further stratified into three categories: infants and toddlers (≤5 years), children (≥5 to <12 years), and adolescents (≥12 to <18 years). Amongst them, the majority was from Punjab (81.6%), while the other regions included were Azad Jammu and Kashmir (14.4%), Islamabad (3.3%), and Khyber Pakhtunkhwa (0.7%). Results: Scabies was the highest reported skin condition with 281 (45.55%) patients, followed by 114 (19.6%) with eczema, 60 (10.3%) with dermatitis, 33 (5.7%) with tinea capitis, 17 (2.9%) with tinea corporis, 16 (2.7%) with impetigo, and 15 (2.6%) with folliculitis. Other conditions include urticaria, burns, infections, pediculosis, tinea inguinalis, tinea faciei, nappy rashes, alopecia, warts, tinea incognito, tinea cruris, and acne vulgaris. The chi-squared test showed a high prevalence of tinea corporis and acne among adolescents (12-17 years), whereas eczema, dermatitis, and impetigo were more prevalent among infants and toddlers. Conclusions: Pets or livestock and poor hygiene were found to be highly reported risk factors for many dermatological conditions like scabies and fungal infections. Dermatological conditions are common in younger individuals, but unfortunately, many children do not receive the desired medical assistance.

Mast cells-fetal mast cells crosstalk with maternal interfaces during pregnancy: Friend or foe?

Mast cells (MC) are hematopoietic immune cells that play a major role during allergic reactions in adults by releasing a myriad of vasoactive and inflammatory mediators. MC seed all vascularized tissues and are most prominent in organs with a barrier function such as skin, lungs, and intestines. These secreted molecules cause mild symptoms such as localized itchiness and sneezing to life-threatening symptoms (i.e., anaphylactic shock). Presently, despite the extensive research on Th2-mediated immune responses in allergic diseases in adults, we are still unable to determine the mechanisms of the role of MC in developing pediatric allergic (PA) disorders. In this review, we will summarize the most recent findings on the origin of MC and discuss the underappreciated contribution of MC in the sensitization phase to maternal antibodies during pregnancy in allergic reactions and other diseases such as infectious diseases. Then, we will lay out potential MC-dependent therapeutic strategies to be considered in future investigations to understand the remaining gaps in MC research for a better quality of life for these young patients.

The Imprint of Exposome on the Development of Atopic Dermatitis across the Lifespan: A Narrative Review

Atopic dermatitis (AD) is a chronic inflammatory skin condition that affects more than 200 million people worldwide, including up to 20% of children and 10% of the adult population. Although AD appears frequently in childhood and often continues into adulthood, about 1 in 4 adults develop the adult-onset disease. The prenatal period, early childhood, and adolescence are considered critical timepoints for the development of AD when the exposome results in long-lasting effects on the immune system. The exposome can be defined as the measure of all the exposures of an individual during their lifetime and how these exposures relate to well-being. While genetic factors could partially explain AD onset, multiple external environmental exposures (external exposome) in early life are implicated and are equally important for understanding AD manifestation. In this review, we describe the conceptual framework of the exposome and its relevance to AD from conception and across the lifespan. Through a spatiotemporal lens that focuses on the multi-level phenotyping of the environment, we highlight a framework that embraces the dynamic complex nature of exposome and recognizes the influence of additive and interactive environmental exposures. Moreover, we highlight the need to understand the developmental origins of AD from an age-related perspective when studying the effects of the exposome on AD, shifting the research paradigm away from the per se categorized exposome factors and beyond clinical contexts to explore the trajectory of age-related exposome risks and hence future preventive interventions.

Divergent Trends in the Prevalence of Children's Asthma, Rhinitis and Atopic Dermatitis and Environmental Influences in the Urban Setting of Zagreb, Croatia

BACKGROUND

Previous studies have reported that the allergy epidemic in developed countries has reached its plateau, while a rise is expected in developing ones. Our aim was to compare the prevalence of allergic diseases among schoolchildren from the city of Zagreb, Croatia after sixteen years.

METHODS

Symptoms of asthma, allergic rhinitis (AR) and atopic dermatitis (AD) and risk factors were assessed using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. An allergic profile was determined by a skin prick test.

RESULTS

The prevalence of current, ever-in-a-lifetime and diagnosed AR of 35.7%, 42.5% and 14.9% and AD of 18.1%, 37.1% and 31.1% demonstrated a significant increase. The asthma prevalence has remained unchanged. The allergen sensitivity rate has remained similar, but pollens have become dominant. Mould and dog exposure are risks for asthma (OR 14.505, OR 2.033). Exposure to cat allergens is protective in AR (OR 0.277). Parental history of allergies is a risk factor in all conditions.

CONCLUSION

Over sixteen years, the prevalence of AR and AD, but not of asthma, have increased. The proportion of atopy has remained high. The AR/AD symptom rise is probably a consequence of increased pollen sensitisation united with high particulate matter concentrations. The stable asthma trend could be a result of decreasing exposures to indoor allergens.

The associations of maternal and children's gut microbiota with the development of atopic dermatitis for children aged 2 years

BACKGROUND

It is critical to investigate the underlying pathophysiological mechanisms in the development of atopic dermatitis. The microbiota hypothesis suggested that the development of allergic diseases may be attributed to the gut microbiota of mother-offspring pairs. The purpose of this study was to investigate the relationship among maternal-offspring gut microbiota and the subsequent development of atopic dermatitis in infants and toddlers at 2 years old.

METHODS

A total of 36 maternal-offspring pairs were enrolled and followed up to 2 years postpartum in central China. Demographic information and stool samples were collected perinatally from pregnant mothers and again postpartum from their respective offspring at the following time intervals: time of birth, 6 months, 1 year and 2 years. Stool samples were sequenced with the 16S Illumina MiSeq platform. Logistic regression analysis was used to explore the differences in gut microbiota between the atopic dermatitis group and control group.

RESULTS

Our results showed that mothers of infants and toddlers with atopic dermatitis had higher abundance of Candidatus_Stoquefichus and Pseudomonas in pregnancy and that infants and toddlers with atopic dermatitis had higher abundance of Eubacterium_xylanophilum_group at birth, Ruminococcus_gauvreauii_group at 1 year and UCG-002 at 2 years, and lower abundance of Gemella and Veillonella at 2 years. Additionally, the results demonstrated a lower abundance of Prevotella in mothers of infants and toddlers with atopic dermatitis compared to mothers of the control group, although no statistical difference was found in the subsequent analysis.

CONCLUSION

The results of this study support that gut microbiota status among mother-offspring pairs appears to be associated with the pathophysiological development of pediatric atopic dermatitis.

Exposure to Microplastics during Early Developmental Stage: Review of Current Evidence

In the last few decades, microplastics (MPs) have been among the emerging environmental pollutants that have received serious attention from scientists and the general population due to their wide range of potentially harmful effects on living organisms. MPs may originate from primary sources (micro-sized plastics manufactured on purpose) and secondary sources (breakdown of large plastic items through physical, chemical, and biological processes). Consequently, serious concerns are escalating because MPs can be easily disseminated and contaminate environments, including terrestrial, air, groundwater, marine, and freshwater systems. Furthermore, an exposure to even low doses of MPs during the early developmental stage may induce long-term health effects, even later in life. Accordingly, this study aims to gather the current evidence regarding the effects of MPs exposure on vital body systems, including the digestive, reproductive, central nervous, immune, and circulatory systems, during the early developmental stage. In addition, this study provides essential information about the possible emergence of various diseases later in life (i.e., adulthood).

Association of the incidence of atopic dermatitis until 3 years old with climate conditions in the first 6 months of life: Japan Environment and Children’s Study (JECS)

Objective

To determine the climate conditions that affect the incidence of atopic dermatitis from infancy to 3 years old.

Study design

We analyzed 100,303 children born from 2011 to 2014 for follow-up until 3 years old using cohort data from the Japan Environment and Children’s Study. The study included 15 Regional Centers, including 19 prefectures across Japan. We used meteorological data of the Japan Meteorological Agency. We calculated the hazard ratio (HR) of the standard deviation and low vs. high mean values of several climate conditions in children in their first 6 months of life to determine the incidence of atopic dermatitis.

Results

The Kaplan–Meier curve showed that children born in the months of October to December had the highest incidence of atopic dermatitis. Among climate conditions, a one standard deviation increase in the temperature (HR = 0.87), minimum temperature (HR = 0.87), and vapor pressure (HR = 0.87) showed the lowest HRs for the incidence of atopic dermatitis. These results were confirmed by an analysis by strata of the birth season. A low vapor pressure (HR = 1.26, p<0.0001) and the combination of a low mean temperature or low mean minimum temperature and low vapor pressure (HR = 1.26, p<0.0001) were associated with the highest incidence of atopic dermatitis. These results were consistent when they were adjusted for a maternal and paternal history of allergy and the prefecture of birth.

Conclusion

Among climate conditions, a low vapor pressure is the most strongly associated with a high incidence of atopic dermatitis. Measuring vapor pressure may be useful for preventing atopic dermatitis.

A Children's Health Perspective on Nano- and Microplastics

BACKGROUND

Pregnancy, infancy, and childhood are sensitive windows for environmental exposures. Yet the health effects of exposure to nano- and microplastics (NMPs) remain largely uninvestigated or unknown. Although plastic chemicals are a well-established research topic, the impacts of plastic particles are unexplored, especially with regard to early life exposures.

OBJECTIVES

This commentary aims to summarize the knowns and unknowns around child- and pregnancy-relevant exposures to NMPs via inhalation, placental transfer, ingestion and breastmilk, and dermal absorption.

METHODS

A comprehensive literature search to map the state of the science on NMPs found 37 primary research articles on the health relevance of NMPs during early life and revealed major knowledge gaps in the field. We discuss opportunities and challenges for quantifying child-specific exposures (e.g., NMPs in breastmilk or infant formula) and health effects, in light of global inequalities in baby bottle use, consumption of packaged foods, air pollution, hazardous plastic disposal, and regulatory safeguards. We also summarize research needs for linking child health and NMP exposures and address the unknowns in the context of public health action.

DISCUSSION

Few studies have addressed child-specific sources of exposure, and exposure estimates currently rely on generic assumptions rather than empirical measurements. Furthermore, toxicological research on NMPs has not specifically focused on child health, yet children's immature defense mechanisms make them particularly vulnerable. Apart from few studies investigating the placental transfer of NMPs, the physicochemical properties (e.g., polymer, size, shape, charge) driving the absorption, biodistribution, and elimination in early life have yet to be benchmarked. Accordingly, the evidence base regarding the potential health impacts of NMPs in early life remains sparse. Based on the evidence to date, we provide recommendations to fill research gaps, stimulate policymakers and industry to address the safety of NMPs, and point to opportunities for families to reduce early life exposures to plastic. https://doi.org/10.1289/EHP9086.

Allergic Diseases: A Comprehensive Review on Risk Factors, Immunological Mechanisms, Link with COVID-19, Potential Treatments, and Role of Allergen Bioinformatics

The prevalence of allergic diseases is regarded as one of the key challenges in health worldwide. Although the precise mechanisms underlying this rapid increase in prevalence are unknown, emerging evidence suggests that genetic and environmental factors play a significant role. The immune system, microbiota, viruses, and bacteria have all been linked to the onset of allergy disorders in recent years. Avoiding allergen exposure is the best treatment option; however, steroids, antihistamines, and other symptom-relieving drugs are also used. Allergen bioinformatics encompasses both computational tools/methods and allergen-related data resources for managing, archiving, and analyzing allergological data. This study highlights allergy-promoting mechanisms, algorithms, and concepts in allergen bioinformatics, as well as major areas for future research in the field of allergology.

Pathogenesis of Children's Allergic Diseases: Refocusing the Role of the Gut Microbiota

Allergic diseases comprise a genetically heterogeneous cluster of immunologically mediated diseases, including asthma, food allergy (FA), allergic rhinitis (AR) and eczema, that have become major worldwide health problems. Over the past few decades, the spread of allergic diseases has displayed an increasing trend, and it has been reported that 22% of 1.39 billion people in 30 countries have a type of allergic disease. Undoubtedly, allergic diseases, which can be chronic, with significant morbidity, mortality and dynamic progression, impose major economic burdens on society and families; thus, exploring the cause of allergic diseases and reducing their prevalence is a top priority. Recently, it has been reported that the gastrointestinal (GI) microbiota can provide vital signals for the development, function, and regulation of the immune system, and the above-mentioned contributions make the GI microbiota a key player in allergic diseases. Notably, the GI microbiota is highly influenced by the mode of delivery, infant diet, environment, antibiotic use and so on. Specifically, changes in the environment can result in the dysbiosis of the GI microbiota. The proper function of the GI microbiota depends on a stable cellular composition which in the case of the human microbiota consists mainly of bacteria. Large shifts in the ratio between these phyla or the expansion of new bacterial groups lead to a disease-promoting imbalance, which is often referred to as dysbiosis. And the dysbiosis can lead to alterations of the composition of the microbiota and subsequent changes in metabolism. Further, the GI microbiota can affect the physiological characteristics of the human host and modulate the immune response of the host. The objectives of this review are to evaluate the development of the GI microbiota, the main drivers of the colonization of the GI tract, and the potential role of the GI microbiota in allergic diseases and provide a theoretical basis as well as molecular strategies for clinical practice.

Prevalence and influencing risk factors of eczema among preschool children in Urumqi city: a cross-sectional survey

Background

Eczema is a chronic inflammatory disease associated with impaired quality of life. We identified indoor environmental risk factors, to provide strong evidence for the prevention and control of eczema in preschool children.

Methods

Using a cross-sectional study with stratified random cluster sampling, we conducted a self-administered questionnaire survey among 8153 parents of children aged 2–8 years in 60 kindergartens in six districts of Urumqi city during August 2019.

Results

Among 8153 preschool children, 12.0% of the children have been diagnosed with eczema. Multivariate logistic regression analysis showed that caesarean section (odds ratio [OR] = 1.18, 95% confidence interval [CI]: 1.03–1.36), being an only child (OR = 1.36, 95% CI: 1.18–1.57), presence of mould or moisture in the mother’s home before pregnancy (OR = 1.53, 95% CI: 1.17–2.00), presence of flies or mosquitoes in the dwelling currently (OR = 1.31, 95% CI: 1.10–1.55), pets kept in the child’s home currently (OR = 1.23, 95% CI: 1.01–1.51), presence of pets during child’s first year (OR = 1.45, 95% CI: 1.14–1.85), and family history of eczema (OR = 3.53, 95% CI: 2.98–4.19) are the risk factors for the development of eczema, whereas ethnicity other than the Han Chinese (OR = 0.77, 95% CI: 0.61–0.96) is a protective factor for eczema.

Conclusion

Preschool children in Urumqi are at a high risk of eczema, particularly those of the Han Chinese ethnicity. Parents should be attentive to the indoor living environment of children and take actions to reduce indoor humidity, pest control and elimination, and avoid raising pets to reduce the risk of development of eczema in children.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02819-5.

Variations in early gut microbiome are associated with childhood eczema

We assessed the relationship between gut microbiome profile and childhood eczema in 172 subjects (age < 3 years, healthy group N = 123, eczema group N = 49) utilizing 16S rRNA gene sequencing. Lower relative abundance of Bifidobacterium was shown to be associated with childhood eczema. Considering that developmental and environmental factors could modify the state of children's gut microbiome, we divided the samples into four age groups: 0-0.5 years, 0.5-1 years, 1-2 years and 2-3 years for farther analyses. Data revealed significant inter-group differences between healthy and eczema samples in all age groups, and decreased microbial diversity was most significantly found in children with eczema of age 2-3 years old. Decreased abundance of Bifidobacterium was a major finding in eczema groups from 0.5-3 years compared to the age matched healthy controls, but not significant in children younger than 6 month old. Of note, Bifidobacterium operational taxonomic units were identified by Random Forest with highly predictive power of 0.83 (AUC = 0.83) in ROC analysis, which also confirmed its role as a key genus that is associated with eczema. To verify the sequencing results, we performed quantitative polymerase chain reaction of Bifidobacterium and Bacteroides in the same cohort, and in a new eczema cohort (N = 57) for validation. Significantly, lower Bifidobacterium quantities were found in both eczema groups with an age range of 0.5-3 years. These results suggest variations in early gut microbiome are associated with childhood eczema.

Effects and mechanism of action of Huang-Lian-Jie-Du-Tang in atopic dermatitis-like skin dysfunction in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Atopic dermatitis (AD), a disorder prevalent during childhood and adulthood, seriously affects the patient's quality of life. Although Huang-Lian-Jie-Du-Tang (HLJDT) has shown anti-inflammatory effects in previous studies, its effects and mechanism of action underlying AD disorder are still largely unknown.

OBJECTIVE

This study explored the anti-inflammatory and immunomodulatory effects of HLJDT on the AD-like dermal disorder, induced in vitro by lipopolysaccharide (LPS)-triggered inflammation, and in vivo by 2,4-dinitrochlorobenzene (DNCB).

MATERIALS AND METHODS

In vivo HLJDT effects were investigated by determining the severity of dermatitis, which consisted of observing signs of skin lesions, visually and through haematoxylin and eosin (HE) staining, in mouse ears and dorsal skin, measuring serum levels of interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-5, IL-6, interferon (IFN)-γ, the tumour necrosis factor (TNF)-α, and determining the splenic index, number of splenic CD4⁺/CD8⁺ T-lymphocytes, as well as the phosphorylation levels of mitogen-activated protein kinases (including MAPKs-p38, ERK, and JNK), IκB-α, and nuclear factor kappa B (NF-κB) (p65) within dermal lesions. Morphological changes in LPS-induced inflammation were observed under a microscope, and ELISA and qPCR assays were used to measure IL-1α, IL-1β, IL-6, and TNF-α expression levels. The protein expression levels of P-ERK/ERK, P-p38/p38, P-JNK/JNK, P-IKβ-α, and P-p65 were measured through western blotting. Additionally, p65 expression was assessed by immunofluorescence, and LPS binding to RAW264.7 cell membrane was studied with laser confocal microscopy.

RESULTS

HLJDT could remarkably mitigate DNCB-induced AD-like lesion symptoms, alleviating inflammatory mediator infiltration in mouse ears and dorsal skin tissue, down-regulating serum expression levels of IL-1α, IL-1β, IL-2, IL-4, IL-5, IL-6, IFN-γ, and TNF-α, normalising the splenic CD4⁺/CD8⁺ T-lymphocyte ratio, and inactivating MAPKs (including p38, ERK, and JNK), IκB-α, and NF-κB (p65) in dorsal skin. Furthermore, HLJDT inhibited LPS-induced differentiation of RAW264.7 cells, as evidenced by the decreased protein and mRNA expression of IL-1α, IL-1β, IL-6, and TNF-α. Additionally, it decreased ERK, p38, JNK, IKβ-α, and p65 phosphorylation levels in the MAPKs/NF-κB pathway, inhibited p65 nuclear translocation, and reduced LPS binding to the RAW264.7 cell membrane.

CONCLUSIONS

HLJDT significantly improved AD-like symptoms via inhibition of the MAPKs/NF-κB pathway. Therefore, administration of HLJDT might be a potential treatment for AD in the clinical setting.

Adhesion of Staphylococcus aureus to Corneocytes from Atopic Dermatitis Patients Is Controlled by Natural Moisturizing Factor Levels

The bacterial pathogen Staphylococcus aureus plays an important role in atopic dermatitis (AD), a chronic disorder that mostly affects children. Colonization of the skin of AD patients by S. aureus exacerbates the disease, but the molecular determinants of the bacterium-skin adhesive interactions are poorly understood. Specifically, reduced levels of natural moisturizing factor (NMF) in the stratum corneum have been shown to be associated with more severe AD symptoms, but whether this is directly related to S. aureus adhesion is still an open question. Here, we demonstrate a novel relationship between NMF expression in AD skin and strength of bacterial adhesion. Low-NMF corneocytes, unlike high-NMF ones, are covered by a dense layer of nanoscale villus protrusions. S. aureus bacteria isolated from AD skin bind much more strongly to corneocytes when the NMF level is reduced. Strong binding forces originate from a specific interaction between the bacterial adhesion clumping factor B (ClfB) and skin ligands. Remarkably, mechanical tension dramatically strengthens ClfB-mediated adhesion, as observed with catch bonds, demonstrating that physical stress plays a role in promoting colonization of AD skin by S. aureus Collectively, our findings demonstrate that patient NMF levels regulate the strength of S. aureus-corneocyte adhesion, the first step in skin colonization, and suggest that the ClfB binding mechanism could represent a potential target for new therapeutic treatments.IMPORTANCE Bacterium-skin interactions play important roles in skin disorders, yet their molecular details are poorly understood. In this study, we decipher the molecular forces at play during adhesion of Staphylococcus aureus to skin corneocytes in the clinically important context of atopic dermatitis (AD), also known as eczema. We identify a unique relationship between the level of natural moisturizing factor (NMF) in the skin and the strength of bacterium-corneocyte adhesion. Bacterial adhesion is primarily mediated by the surface protein clumping factor B (ClfB) and is enhanced by physical stress, highlighting the role of protein mechanobiology in skin colonization. Similar to a catch bond behavior, this mechanism represents a promising target for the development of novel antistaphylococcal agents.

Microbial eczema: possibilities of correction at the present stage

Microbial eczema is a chronic recurrent dermatosis characterized by evolutionary polymorphism of the elements of the rash, sputum, itching, allergic reaction of the sensitized skin to the products of the decay of microorganisms and their toxins, developing against the background of a long-existing pyogenic focus in violation of the most important regulatory systems of the body.Purpose: to study the biocenosis of the skin in patients with microbial eczema and to evaluate the clinical efficacy and safety of the cream “Tetraderm” in such patients.Materials and methods. Patients with microbial eczema were observed, randomly selected into two groups. All patients studied biocenosis of the skin before and after treatment. Patients of the study group received topical therapy with the cream “Tetraderm”. External therapy for patients of the comparison group was carried out with cream of mometasone furoate in combination with erythromycin and clotrimazole ointments. The effectiveness of the therapy was evaluated taking into account the clinical dynamics of the skin process, bacteriological data on the content of pustules and detachable erosion, calculation of the EASI and DIJ indices.Results. A comparative analysis of the biocenosis of microbial eczema foci in patients of both groups at the end of therapy showed a higher severity of disbiotic changes in the comparison group. As a result of our study found that patients who used the cream “Tetraderm”, there was a more rapid regression of dermatosis, almost complete suppression of pathogenic bacterial flora, a significant improvement in the quality of life.Conclusion. The biocenosis of the skin of patients with microbial eczema was characterized by a high degree of contamination of Staphylococcus aureus and Staphylococcus epidermidis, against the background of the average verification of Streptococcus spp., Candida spp. The combination of pronounced anti-inflammatory, antibacterial, antimicotic and regenerating effects of the cream “Tetraderm” causes its high efficiency and prospects of use as a drug of choice of topical monotherapy of microbial eczema.

Staphylococcal Biofilms in Atopic Dermatitis

PURPOSE OF REVIEW

Atopic dermatitis (AD) is a chronic, relapsing inflammatory skin disorder that is a major public health burden worldwide. AD lesions are often colonized by Staphylococcus aureus and Staphylococcus epidermidis. An important aspect of Staphylococcus spp. is their propensity to form biofilms, adhesive surface-attached colonies that become highly resistant to antibiotics and immune responses, and recent studies have found that clinical isolates colonizing AD skin are often biofilm-positive. Biofilm formation results in complex bacterial communities that have unique effects on keratinocytes and host immunity. This review will summarize recent studies exploring the role of staphyloccocal biofilms in atopic dermatitis and the implications for treatment.

RECENT FINDINGS

Recent studies suggest an important role for biofilms in the pathogenesis of numerous dermatologic diseases including AD. S. aureus biofilms have been found to colonize the eccrine ducts of AD skin, and these biofilms influence secretion of keratinocyte cytokines and trigger differentiation and apoptosis of keratinocytes. These activities may act to disrupt barrier function and promote disease pathogenesis as well as allergen sensitization. Formation of biofilm is a successful strategy that protects the bacteria from environmental danger, antibiotics, and phagocytosis, enabling chronic persistence in the host. An increasing number of S. aureus skin isolates are resistant to conventional antibiotics, and staphylococcal biofilm communities are prevalent on the skin of individuals with AD. Staphylococcal colonization of the skin impacts skin barrier function and plays multiple important roles in AD pathogenesis.

Asthma-like airway inflammation and responses in a rat model of atopic dermatitis induced by neonatal capsaicin treatment

Recent studies have shown that approximately 70% of patients with severe atopic dermatitis (AD) develop asthma. Development of AD in infancy and subsequent other atopic diseases such as asthma in childhood is referred to as atopic march. However, a causal link between the diseases of atopic march has remained largely unaddressed, possibly due to lack of a proper animal model. Recently, we developed an AD rat model showing chronically relapsing dermatitis and scratching behaviors induced by neonatal capsaicin treatment. Here, we investigated whether our model also showed asthmatic changes, with the aim of expanding our AD model into an atopic march model. First, we confirmed that capsaicin treatment (50 mg/kg within 24 h after birth) induced dermatitis and scratching behaviors until 6 weeks of age. After that, the mRNA expression of Th1 and Th2 cytokines, such as IFN-γ and TNF-α, and IL-4, IL-5, and IL-13, respectively, was quantified with quantitative real-time polymerase chain reaction in the skin and the lungs. The number of total cells and eosinophils was counted in bronchoalveolar lavage (BAL) fluid. The levels of IgE in the serum and BAL fluid were determined with enzyme-linked immunosorbent assay. Paraffin-embedded sections (4 μm) were stained with hematoxylin/eosin to analyze the morphology of the lung and the airway. Airway responsiveness was measured in terms of airway resistance and compliance using the flexiVent system. In the capsaicin-treated rats, persistent dermatitis developed, and scratching behaviors increased over several weeks. The levels of IgE in the serum and BAL fluid as well as the mRNA expression of Th2 cytokines, including IL-4, IL-5, and IL-13, in both the skin and the lungs were elevated, and the number of eosinophils in the BAL fluid was also increased in the capsaicin-treated rats compared to control rats. Morphological analysis of the airway revealed smooth muscle hypertrophy and extensive mucus plug in the capsaicin-treated rats. Functional studies demonstrated an increment of the airway resistance and a decrement of lung compliance in the capsaicin-treated rats compared to control rats. Taken together, our findings suggested that neonatal capsaicin treatment induced asthma-like airway inflammation and responses in juvenile rats.

Atopic dermatitis is associated with a fivefold increased risk of polysensitisation in children

AIM

It has been hypothesised that in atopic dermatitis, the dysfunctional skin barrier facilitates the transcutaneous presentation of allergens to the immune system. This study examined whether atopic dermatitis increased the likelihood of polysensitisation, namely sensitisation to five or more allergens.

METHODS

We examined the electronic hospital charts of 1743 children aged 0-17 years who had visited primary or secondary care physicians with allergic symptoms, whose blood was examined for the presence of specific immunoglobulin E (IgE) to the 10 most common inhaled and food allergens and whose files contained documentation of the presence of atopic dermatitis and other skin disorders. Sensitisation was defined as a specific IgE level of ≥0.35 kU/L.

RESULTS

Polysensitisation was more common in children with atopic dermatitis (268/1197, 22.4%) than those without (30/546, 5.5%, p < 0.001). This remained significant after adjustment for gender and age in a multiple logistic regression model (odds ratio: 5.63, 95% confidence interval 3.77-8.40). Other skin disorders did not show an increased risk of polysensitisation (5/97, 5.2%).

CONCLUSION

Polysensitisation was considerably more common in children with atopic dermatitis than those without. This supports the hypothesis that sensitisation occurs through a defective skin barrier and appears to be specific for atopic dermatitis.

Gene-Environment Interactions-What Can These Tell Us about the Relationship between Asthma and Allergy?

Asthma is a common condition, which is associated with atopy and allergic conditions including hay fever, eczema, and food allergies. Asthma and atopy are both complex conditions where genetic and environmental factors are implicated in causation. Interactions between genetic and environmental factors, likely via epigenetic mechanisms, are widely thought to be important in determining the risk for developing asthma and atopy. The nature of the relationship between asthma and atopy is unclear and the answer to the question "does atopy cause asthma?" remains unknown. This review explores the relationship between asthma and atopy from a gene-environment interaction perspective and tackles the question "are similar gene-environment interactions present for asthma and atopy?" The main finding is that gene-environment interactions are described for asthma and atopy in children but these interactions are seldom sought for both asthma and atopy in the same population. In the few instances where a gene-environment interaction is related to both asthma and atopy, there is no consistent evidence that similar interactions are common to asthma and atopy. Many plausible gene-environment interactions for asthma and atopy are yet to be explored. Overall, from the gene-environment interaction perspective, there is absence of evidence to better understand the complex relationship between asthma and atopy.

Associations of gestational and early life exposures to ambient air pollution with childhood atopic eczema in Shanghai, China

Whether ambient air pollution is associated with childhood atopic eczema is controversial. In this paper, we selected 3358 preschool children who had not altered residences since pregnancy from a cross-sectional study during 2011-2012 in Shanghai, China, and obtained parent-reported data regarding childhood atopic eczema using an improved ISAAC questionnaire. We recorded daily concentrations of SO₂, NO₂, and PM₁₀ throughout the child's lifetime (2006-2012), and calculated period-averaged concentrations for each district where the child lived to represent the child's exposure levels of these pollutants during different periods. In the multiple logistic regression analyses adjusted for potential confounders as well as for the other pollutants in the same periods, childhood atopic eczema was significantly associated with increments of NO₂ in the approximate interquartile range (20μg/m³) during gestational period (adjusted OR, 95% CI for eczema lifetime-ever: 1.80, 1.29-2.49; for eczema in the year prior to the survey: 2.32, 1.57-3.43) and during the first year of life (2.00, 1.40-2.84; 2.16, 1.43-3.28). Exposure to elevated NO₂ in the first two years, three years and total lifetime, as well as exposure to mixtures containing NO₂ in each of these periods, were consistently associated with increased likelihood of childhood eczema. The highest odds ratios were found between exposure to a mixture of SO₂ and NO₂ during total lifetime (increment: 35μg/m³) and childhood eczema (adjusted OR, 95% CI: 2.80, 1.75-4.48; 3.50, 1.98-6.19). No significant associations were found between childhood eczema and ambient SO₂ and PM₁₀ individually or in mixtures. This study indicates that gestational and lifetime exposures to ambient NO₂ are risk factors for atopic eczema in childhood. Exposure to ambient SO₂ and PM₁₀ may enhance the effect of NO₂ exposure on childhood eczema.

Altered Gut Microbiota Composition Associated with Eczema in Infants

Eczema is frequently the first manifestation of an atopic diathesis and alteration in the diversity of gut microbiota has been reported in infants with eczema. To identify specific bacterial communities associated with eczema, we conducted a case-control study of 50 infants with eczema (cases) and 51 healthy infants (controls). We performed high-throughput sequencing for V3–V4 hypervariable regions of the 16S rRNA genes from the gut fecal material. A total of 12,386 OTUs (operational taxonomic units) at a 97% similarity level were obtained from the two groups, and we observed a difference in taxa abundance, but not the taxonomic composition, of gut microbiota between the two groups. We identified four genera enriched in healthy infants: Bifidobacterium, Megasphaera, Haemophilus and Streptococcus; and five genera enriched in infants with eczema: Escherichia/Shigella, Veillonella, Faecalibacterium, Lachnospiraceae incertae sedis and Clostridium XlVa. Several species, such as Faecalibacterium prausnitzii and Ruminococcus gnavus, that are known to be associated with atopy or inflammation, were found to be significantly enriched in infants with eczema. Higher abundance of Akkermansia muciniphila in eczematous infants might reduce the integrity of intestinal barrier function and therefore increase the risk of developing eczema. On the other hand, Bacteroides fragilis and Streptococcus salivarius, which are known for their anti-inflammatory properties, were less abundant in infants with eczema. The observed differences in genera and species between cases and controls in this study may provide insight into the link between the microbiome and eczema risk.

Timing of eczema onset and risk of food allergy at 3 years of age: A hospital-based prospective birth cohort study

BACKGROUND

Although recent studies suggest that eczema in early childhood is important in the development of food allergy, the importance of the timing of eczema onset has not been fully clarified.

OBJECTIVE

This study aim to identify an association between the timing of eczema onset and development of food allergy in a prospective birth cohort study.

METHODS

Data were obtained from the Tokyo Children's Health, Illness and Development (T-CHILD) study, which is a hospital-based birth cohort study currently in progress in Japan. A total of 1550 children were born to the recruited women. Outcome data for children were collected from questionnaires completed at 6 months, 1 and 3 years of age. Association between the timing of eczema onset and development of food allergy was estimated by logistic regression analyses. All analysis were performed using SPSS software with a two-sided 5% significance level.

RESULTS

Eczema in the first year of life was a significant risk factor in multivariate analysis (aOR 3.90, 95% CI 2.34-6.52, p<0.001). In each age (by month) stratum, infants with onset of eczema within the first 1-2 months after birth had the highest risk of food allergy at 3 years of age (aOR 6.61, 95% CI 3.27-13.34, p<0.001).

CONCLUSION

Infants with early eczema onset (especially within the first 1-4 months after birth) were found to have an increased risk of developing food allergy at 3 years of age. Our findings may contribute to a better understanding of the timing of eczema onset as a potentially modifiable risk factor and to defining those who may need to be on guard for food allergy.

Parental smoking and development of allergic sensitization from birth to adolescence

Background

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

Methods

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

Results

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

Conclusions

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

Predictive factors of persistent infantile atopic dermatitis up to 6 years old in Taiwan: a prospective birth cohort study

BACKGROUND

Atopic dermatitis affects 15-30% of children worldwide. Onset of disease usually occurs within the first year of life, over half of which regress by 6 years of age. The aim of this study was to investigate the risk factors related to the persistence of infantile atopic dermatitis.

METHODS

In this birth cohort study, patients were enrolled prenatally and followed until 6 years of age; 246 patients had infantile atopic dermatitis at 6 months of age. Family history, maternal and paternal total and specific Immunoglobulin E (IgE) levels, and cord blood IgE were recorded. Clinical examination, questionnaire survey, and blood samples for total and specific IgE of the children were collected at each follow-up visit.

RESULTS

Of the 246 patients with infantile atopic dermatitis at 6 months of age, 48 patients had persisted atopic dermatitis at 6 years of age (19.5%). Risk factors associated with persistent infantile atopic dermatitis included egg white sensitization (odds ratio: 3.801, P = 0.020), and atopic dermatitis involving two or more areas at 6 months old (odds ratio: 2.921, P = 0.018) after multivariate analysis with logistic regression. Patients with persistent infantile atopic dermatitis had a higher risk of asthma before 6 years old (39.6% vs 24.2%, P = 0.032).

CONCLUSION

Egg white sensitization and the initial involvement of two or more areas at 6 months of age were associated with the persistent infantile atopic dermatitis. Patients with persistent infantile atopic dermatitis are more likely to develop asthma by 6 years of age.

A longitudinal study of skin barrier function in pregnancy and the postnatal period

BACKGROUND

It is unknown whether skin's barrier function changes in pregnancy. Trans Epidermal Water Loss (TEWL) refers to the total amount of water loss through the skin and TEWL can be measured non-invasively as an index of skin barrier function. We measured TEWL during and after pregnancy to evaluate pregnancy-related skin barrier function.

METHODS

This was a prospective, longitudinal cohort study of 52 low-risk, first-time pregnant women nested within the Screening for Pregnancy Endpoints (SCOPE) Ireland study. TEWL (gwater/m2/h) was measured three times during pregnancy: 19-21 weeks, 27-32 weeks and 36 weeks; and three times postnatally: 2-4 days, 2 months and 6 months post-delivery. Data were analysed using SPSS 18.0 and P > 0.05 was considered statistically significant.

RESULTS

A rise in TEWL was seen between each visit with the highest readings, exceeding the normal range of 0-20 gwater/m(2)/h, recorded at two months post-delivery. Forty women attended at two months post-delivery of whom 22 women had an average reading between 0 and 20 gwater/m(2)/h; 10 women had an average reading between 21 and 40 gwater/m(2)/h and 8 women had an average reading between 41 and 75 gwater/m(2)/h. Readings had returned to an average of 0-20 gwater/m(2)/h at six months postnatally.

CONCLUSION

TEWL increases slightly in pregnancy and the postnatal period. The clinical significance of this is unclear and requires further investigation.

Pre- and postnatal exposure to parental smoking and allergic disease through adolescence

OBJECTIVES

To examine the role of prenatal and postnatal second-hand tobacco smoke (SHS) exposure on asthma, rhinitis, and eczema development up to 16 years of age.

METHODS

A birth cohort of 4089 children was followed for 16 years. Information on parental smoking habits, lifestyle factors, and symptoms of allergic disease was gathered using repeated parental questionnaires. Generalized estimating equations assessed the overall and age-specific associations between SHS exposure and allergic disease at ages 1 to 16 years.

RESULTS

Exposure to SHS in utero was associated with an overall elevated risk of developing asthma up to 16 years (odds ratio [OR] = 1.45; 95% confidence interval [CI], 1.15-1.83) but not for rhinitis or eczema. After additional adjustment for parental smoking throughout childhood, excess overall risks for asthma remained statistically significant. Moreover, a dose-dependent pattern with SHS was observed. Exposure to SHS during infancy was associated with an overall elevated risk of asthma (OR = 1.23; 95% CI, 1.01-1.51), rhinitis (OR = 1.18; 95% CI, 1.01-1.39), and eczema (OR = 1.26; 95% CI, 1.09-1.45) up to 16 years. When age-specific associations were examined, the elevated risks related to SHS exposure in utero or during infancy were mostly confined to early childhood for asthma and rhinitis, whereas the excess risk of eczema appeared greatest at later ages.

CONCLUSIONS

Our findings indicate that early SHS exposure, in utero or during infancy, influences the development of allergic disease up to adolescence. Excess risks for asthma and rhinitis were seen primarily in early childhood, whereas those for eczema occurred at later ages.

Interplay of filaggrin loss-of-function variants, allergic sensitization, and eczema in a longitudinal study covering infancy to 18 years of age

Background

Immune specific genes as well as genes regulating the formation of skin barrier are major determinants for eczema manifestation. There is a debate as to whether allergic sensitization and filaggrin gene (FLG) variants lead to eczema or FLG variants and eczema increase the risk of allergic sensitization. To investigate the time-order between eczema and allergic sensitization with respect to FLG variants, data from a large prospective study covering infancy to late adolescence were analyzed.

Methodology/Principal Findings

Repeated measurements of eczema and allergic sensitization (documented by skin prick tests) at ages 1, 2, 4, 10, and 18 years were ascertained in the Isle of Wight birth cohort (n = 1,456). Three transition periods were analyzed: age 1-or-2 to 4, 4 to 10, and 10 to 18 years. FLG variants were genotyped in 1,150 participants. Over the three transition periods, in temporal sequence analyses of initially eczema-free participants, the combined effect of FLG variants and allergic sensitization showed a 2.92-fold (95% CI: 1.47–5.77) increased risk ratio (RR) of eczema in subsequent examinations. This overall risk was more pronounced at a younger age (transition period 1-or-2 to 4, RR = 6.47, 95% CI: 1.96–21.33). In contrast, FLG variants in combination with eczema showed a weaker, but significant, risk ratio for subsequent allergic sensitization only up to 10 years of age.

Conclusions/Significance

Taking the time order into account, this prospective study demonstrates for the first time, that a combination of FLG variants and allergic sensitization increased the risk of eczema in subsequent years. Also FLG variants interacted with eczema and increased the risk of subsequent allergic sensitization, which, was limited to the younger age. Hence, early restoration of defective skin barrier could prevent allergic sensitization and subsequently reduce the risk of eczema development.

Mikrobnaya ekzema: novye vozmozhnostikombinirovannoy topicheskoy terapii

The authors assessed clinical efficacy and safety of Supirocin-B for patients suffering from microbial eczema. The dynamic assessment of EASI, Dermatological Index of Symptom Scale, DLQI and results of bacterioscopic examination showed that evident positive results of the use of Supirocin-B in patients suffering from microbial eczema are related to the strong antibacterial action of such a topical antibiotic as Mupirocin as well as high topical anti-inflammatory action of betamethasone dipropionate.

Th2 Cytokines and Atopic Dermatitis

Atopic dermatitis (AD), a chronic relapsing inflammatory skin disease, is increasing in prevalence around the world. Intensive research is ongoing to understand the mechanisms involved in the development of AD and offer new treatment options for patients suffering from AD. In this review, we highlight the importance of allergic Th2 responses in the development of the disease and summarize relevant literature, including genetic studies, studies of human skin and mechanistic studies on keratinocytes and mouse models of AD. We discuss the importance of the skin barrier and review recent findings on the pro-Th2 cytokines TSLP, IL-25, and IL-33, notably their ability to polarize dendritic cells and promote Th2 responses. After a brief update on the contribution of different T-cell subsets to AD, we focus on Th2 cells and the respective contributions of each of the Th2 cytokines (IL-4, IL-13, IL-5, IL-31, and IL-10) to AD. We conclude with a brief discussion of the current gaps in our knowledge and technical limitations.