Atopic Dermatitis and Food Allergy: A Complex Interplay What We Know and What We Would Like to Learn

Atopic dermatitis: a comprehensive updated review of this intriguing disease with futuristic insights

Atopic dermatitis (AD) is a paradigmatic prevalent, long-lasting, and inflammatory skin condition with a diverse range of clinical manifestations. The etiology and clinical symptoms of AD are influenced by complex pathophysiological processes, which involve a strong genetic component, epidermal dysfunction, and immunological dysregulation, and a strong influence of other physiological and environmental factors. The FDA has approved targeted and well-tolerated immunomodulators including biologics like dupilumab and crisaborole, and small molecules such as baricitinib, as novel therapies for AD. They effectively treat AD but are too expensive for most patients. The review provides an update on the state of knowledge of AD pathogenesis, discusses the available diagnostic and scoring indices, and provides a scientific foundation for treatment methods for AD. This review also presents data on clinical efficacy of innovative treatments' considering recent guidelines, emphasizing the newest medications and ongoing trials. Finally, the new implication of artificial intelligence (AI) in AD management is explored, where AI can speed up diagnosis and therapy. The PubMed, Google Scholar, and ScienceDirect databases were used for this review.

Prevalence of food allergy and its association with atopic dermatitis in Iran: Results from the PERSIAN birth cohort

Background

The incidence of food allergy (FA) has been increasing worldwide, causing growing concern on a global scale.

Objective

This birth cohort study analyzes the incidence of reported FA and other atopic comorbidities in children from birth to age 2 years who were living in 4 urban and semiurban areas in Iran.

Methods

Children were followed from birth until age 24 months, with follow-up questionnaires administered through parent or guardian interviews conducted when the children were aged 2, 4, 6, 12, and 24 months.

Results

The rate of physician-diagnosed FA reported by parents or guardians was higher than expected, with a cumulative incidence of 7.7% in children younger than 24 months. The highest prevalence of FA was found in Yazd, the most urban of the 4 cities studied. Breast-feeding was associated with a decreased cumulative risk of FA at age 12 months, with only 5% of breast-fed children developing parent-reported pediatrician-diagnosed FA compared with 13% of infants who never received breast milk after birth.

Conclusion

This study provides valuable insight into the incidence of FA in the Middle East, which has previously not been reported on, and it is crucial in our understanding of global FA prevalence. The study demonstrates a high incidence of FA in an area with historically lower rates and confirms that breast-feeding does prevent FA during infancy in this population.

Prevalence of Bacterial Pathogens Isolated from Canines with Pyoderma and Otitis Externa in Korea: A Systematic Review and Meta-Analysis

Bacterial skin infections, particularly pyoderma and otitis externa, are widespread in dogs, primarily caused by Staphylococcus and Pseudomonas species. This study evaluates the prevalence and types of bacterial pathogens in affected dogs in South Korea using a meta-analytical approach. Following the PRISMA guidelines, five electronic databases were searched for relevant studies published between 1990 and 2024. Three researchers independently performed data extraction and quality assessment. A subgroup analysis explored the variability in pathogen prevalence across studies based on bacterial genus, bacterial species, publication year, sampling year, sampling location, infection type, diagnostic method, and sample size. Publication bias was evaluated using funnel plots and Egger's regression test, with all analyses conducted using the R program. Of the 944 articles, 29 met the eligibility criteria. The pooled bacterial prevalence among infected dogs was 99.95% (95%CI: 99.85-100). Staphylococcus was the most prevalent genus (95.93%), followed by Pseudomonas (48.43%), Enterococcus (20.32%), and Escherichia (17.63%). The most common species were Staphylococcus pseudintermedius (78.89%), Staphylococcus intermedius (71.43%), and Pseudomonas aeruginosa (46.13%). This study underscores the need for comprehensive treatment strategies targeting Gram-negative and Gram-positive bacteria, emphasizing further research on antimicrobial resistance patterns and treatment efficacy to enhance canine health outcomes in South Korea.

Association Between Food Allergy Status and Atopic Dermatitis Control and Persistence: A Longitudinal Analysis of the Pediatric Eczema Elective Registry

Atopic dermatitis (AD) and food allergies (FA) are closely linked manifestations of atopic disease, sharing immunological pathways that contribute to their chronicity and mutual exacerbation. However, the long-term impact of FA on AD remains incompletely understood. To address this knowledge gap, we analyzed 8015 children from the Pediatric Eczema Elective Registry (PEER), exploring the relationship between FA status as an exposure and AD control as an outcome at enrollment, as well as AD persistence as another outcome over 10 years. Our results indicate that at enrollment, children with any FA had significantly higher odds of having uncontrolled AD, and over the course of 10 years, they were more likely to experience persistent AD compared to those without any FA. These associations were particularly pronounced in subgroup analyses of milk, egg, and peanut allergies, highlighting the importance of recognizing FA as a significant prognostic factor in managing long-term AD outcomes in comorbid cases.

Atopic dermatitis

Atopic dermatitis (AD) is a common, chronic skin disorder that can significantly impact the quality of life (QoL) of affected individuals as well as their families. Although the pathogenesis of the disorder is not yet completely understood, it appears to result from the complex interplay between defects in skin barrier function, environmental and infectious agents, and immune dysregulation. There are no diagnostic tests for AD; therefore, the diagnosis is based on specific clinical criteria that take into account the patient's history and clinical manifestations. Successful management of the disorder requires a multifaceted approach that involves education, optimal skin care practices, anti-inflammatory treatment with topical corticosteroids, topical calcineurin inhibitors (TCIs) and/or phosphodiesterase-4 (PDE-4) inhibitors, the management of pruritus, and the treatment of skin infections. Systemic immunosuppressive agents may also be used, but are generally reserved for severe flare-ups or more difficult-to-control disease. Newer systemic agents, such as Janus Kinase (JAK) inhibitors and biologics, have a more favourable safety and efficacy profile than the older, traditional systemic immunosuppressives. Topical corticosteroids are the first-line pharmacologic treatments for AD, and evidence suggests that these agents may also be beneficial for the prophylaxis of disease flare-ups. Although the prognosis for patients with AD is generally favourable, those patients with severe, widespread disease and concomitant atopic conditions, such as asthma and allergic rhinitis, are likely to experience poorer outcomes. Newer systemic agents have been approved which are greatly improving the QoL of these patients.

Association between frozen embryo transfer and childhood allergy: a retrospective cohort study

RESEARCH QUESTION

Does frozen embryo transfer (FET) increase the risk of allergic diseases in offspring?

DESIGN

This study followed up 653 singleton children: 166 born through FET and 487 born through natural conception. Demographic characteristics, perinatal information and allergic diseases of children and their parents were collected through clinical medical systems and questionnaires. Among these 653 children, allergen-specific immunoglobulin E (IgE) testing was performed using peripheral blood samples collected from 207 children: 145 in the FET group and 62 in the natural conception group. The prevalence of allergic diseases and positive rates of allergen-specific IgE testing were compared between the two groups with adjustments for confounding factors.

RESULTS

The prevalence of food allergy was significantly higher in children born through FET compared with children born through natural conception (adjusted OR = 3.154, 95% CI 1.895-5.250; P < 0.001). In addition, positive rates of food allergen sensitization were higher in children in the FET group compared with children in the natural conception group (adjusted OR = 5.769, 95% CI 2.859-11.751, P < 0.001). Children in the FET group had a higher positive sensitization rate to at least one allergen compared with children in the natural conception group (adjusted OR = 3.127, 95% CI 1.640-5.961, P < 0.001). No association was observed between FET and other allergic diseases, including asthma (P = 0.136), atopic dermatitis (P = 0.130) and allergic rhinitis (P = 0.922). Allergen sensitization IgE testing indicated no differences between the two groups in terms of positive sensitization rates of other common allergens, including animal and insect allergens (P = 0.627), inhaled outdoor allergens (P = 0.915) and inhaled outdoor allergens (P = 0.544).

CONCLUSION

This study suggests that children born through FET have increased risk of developing food allergy in early childhood.

Proteomic analysis of cardiovascular disease-associated proteins in Korean patients with moderate-to-severe atopic dermatitis

Background

Cardiovascular diseases (CVDs) have been associated with atopic dermatitis (AD), including in Korean patients. Previous studies on AD have primarily focused on patients of European ancestry, while the Asian endotype exhibits distinct characteristics. This study aimed to characterize the blood proteomic signature of Korean patients with moderate-to-severe AD, with an emphasis on proteins related to CVDs.

Methods

A total of 78 participants, including 39 patients with moderate-to-severe AD and 39 age- and sex-matched healthy controls, were enrolled. Blood proteomics analysis was performed using the Olink CVD II panel, which measures the expression levels of 92 proteins associated with CVDs.

Results

Unsupervised hierarchical clustering revealed 44 upregulated and 5 downregulated proteins in AD patients compared to healthy controls. Principal component analysis (PCA) effectively distinguished AD patients from healthy subjects based on the complete set of proteins or the subset of upregulated proteins. A multiple linear regression model comprising CCL17 and FGF21 showed a strong correlation with disease severity (R = 0.619). Correlation analysis identified 25 highly correlated proteins, including STK4, ITGB1BP2, and DECR1, which were newly found to be upregulated in Korean AD patients. Pathway analysis highlighted the involvement of these proteins in vascular system, inflammation, and lipid metabolism pathways.

Conclusion

The blood proteomic profile of moderate-to-severe AD patients in Korea differed from healthy controls using the CVD II panel. This study provides potential biomarkers for the AD-CVD association and insights into the pathways contributing to this relationship in the Korean population.

Skin as the target for allergy prevention and treatment

The fact that genetic and environmental factors could trigger disruption of the epithelial barrier and subsequently initiate a TH2 inflammatory cascade conversely proposes that protecting the same barrier and promoting adequate interactions with other organs, such as the gut, may be crucial for lowering the risk and preventing atopic diseases, particularly, food allergies. In this review, we provide an overview of structural characteristics that support the epithelial barrier hypothesis in patients with atopic dermatitis, including the most relevant filaggrin gene mutations, the recent discovery of the role of the transient receptor potential vanilloid 1, and the role involvement of the microbiome in healthy and damaged skin. We present experimental and human studies that support the mechanisms of allergen penetration, particularly the dual allergen exposure and the outside-in, inside-out, and outside-inside-outside hypotheses. We discuss classic skin-targeted therapies for food allergy prevention, including moisturizers, steroids, and topical calcineurin inhibitors, along with pioneering trials proposed to change their current use (Prevention of Allergy via Cutaneous Intervention and Stopping Eczema and ALlergy). We provide an overview of the novel therapies that enhance the skin barrier, such as probiotics and prebiotics topical application, read-through drugs, direct and indirect FLG replacement, and interleukin and janus kinases inhibitors. Last, we discuss the newer strategies for preventing and treating food allergies in the form of epicutaneous immunotherapy and the experimental use of single-dose of adeno-associated virus vector gene immunotherapy.

Exploring the Complexities of Atopic Dermatitis: Pathophysiological Mechanisms and Therapeutic Approaches

Atopic dermatitis (AD) is a prevalent inflammatory skin condition impacting both children and adults globally, with a prevalence of 15-30%. It ranks as the most prevalent skin disorder based on disability-adjusted life-years by the World Health Organization. It presents with symptoms like skin irritation, redness, dryness, itchiness, and vesicular blisters and commonly coexists with other atopic symptoms like allergic rhinitis, asthma, and food allergies. The pathophysiology involves a complex interplay of genetic predispositions, immunological dysfunctions, and environmental factors leading to tissue inflammation and disrupted skin barrier integrity. Alopecia areata is characterized by nonscarring hair loss and shares correlations with AD including a higher prevalence of atopic diseases, shared intracellular mechanisms involving the JAK-STAT pathway, and potential treatment overlap such as dupilumab. These correlations could direct new areas of research and increased insight for both diseases. Treatment of AD requires a personalized approach due to its complex, multifactorial nature integrating nonpharmacological interventions like skin hydration and trigger avoidance as well as topical and systemic approaches, if necessary, with topical corticosteroids being the first line for flares; long term corticosteroid use poses risk for adverse effects like skin atrophy. Severe cases may require systemic treatments or phototherapy. Future treatment prospects include targeting the dysbiotic microbiome and identifying biomarkers for tailored therapeutic strategies, emphasizing the importance of personalized medicine in optimizing AD management.

Emollient application from birth to prevent eczema in high-risk children: the BEEP RCT

Background

Atopic eczema is a common childhood skin problem linked with asthma, food allergy and allergic rhinitis that impairs quality of life.

Objectives

To determine whether advising parents to apply daily emollients in the first year can prevent eczema and/or other atopic diseases in high-risk children.

Design

A United Kingdom, multicentre, pragmatic, two-arm, parallel-group randomised controlled prevention trial with follow-up to 5 years.

Setting

Twelve secondary and four primary care centres.

Participants

Healthy infants (at least 37 weeks' gestation) at high risk of developing eczema, screened and consented during the third trimester or post delivery.

Interventions

Infants were randomised (1 : 1) within 21 days of birth to apply emollient (Doublebase Gel®; Dermal Laboratories Ltd, Hitchin, UK or Diprobase Cream®) daily to the whole body (excluding scalp) for the first year, plus standard skin-care advice (emollient group) or standard skin-care advice only (control group). Families were not blinded to allocation.

Main outcome measures

Primary outcome was eczema diagnosis in the last year at age 2 years, as defined by the UK Working Party refinement of the Hanifin and Rajka diagnostic criteria, assessed by research nurses blinded to allocation. Secondary outcomes up to age 2 years included other eczema definitions, time to onset and severity of eczema, allergic rhinitis, wheezing, allergic sensitisation, food allergy, safety (skin infections and slippages) and cost-effectiveness.

Results

One thousand three hundred and ninety-four newborns were randomised between November 2014 and November 2016; 693 emollient and 701 control. Adherence in the emollient group was 88% (466/532), 82% (427/519) and 74% (375/506) at 3, 6 and 12 months. At 2 years, eczema was present in 139/598 (23%) in the emollient group and 150/612 (25%) in controls (adjusted relative risk 0.95, 95% confidence interval 0.78 to 1.16; p = 0.61 and adjusted risk difference -1.2%, 95% confidence interval -5.9% to 3.6%). Other eczema definitions supported the primary analysis. Food allergy (milk, egg, peanut) was present in 41/547 (7.5%) in the emollient group versus 29/568 (5.1%) in controls (adjusted relative risk 1.47, 95% confidence interval 0.93 to 2.33). Mean number of skin infections per child in the first year was 0.23 (standard deviation 0.68) in the emollient group versus 0.15 (standard deviation 0.46) in controls; adjusted incidence rate ratio 1.55, 95% confidence interval 1.15 to 2.09. The adjusted incremental cost per percentage decrease in risk of eczema at 2 years was £5337 (£7281 unadjusted). No difference between the groups in eczema or other atopic diseases was observed during follow-up to age 5 years via parental questionnaires.

Limitations

Two emollient types were used which could have had different effects. The median time for starting emollients was 11 days after birth. Some contamination occurred in the control group (< 20%). Participating families were unblinded and reported on some outcomes.

Conclusions

We found no evidence that daily emollient during the first year of life prevents eczema in high-risk children. Emollient use was associated with a higher risk of skin infections and a possible increase in food allergy. Emollient use is unlikely to be considered cost-effective in this context.

Future research

To pool similar studies in an individual patient data meta-analysis.

Trial registration

This trial is registered as ISRCTN21528841.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 12/67/12) and is published in full in Health Technology Assessment; Vol. 28, No. 29. See the NIHR Funding and Awards website for further award information.

Metabolomics in Children Cow's Milk Protein Allergy: Possible Contribution from a System Biology Approach?

One of the most frequent triggers of food anaphylaxis in pediatric age but also among the most common, early, and complex causes of childhood food allergy is cow's milk protein allergy (CMPA). The diagnostic course and management of this allergy is defined in a complex clinical picture due to several factors. First of all, the epidemiological data are not uniform, mainly as a consequence of the diagnostic methodology used in the various studies and the different age ranges covered. In addition, there is the complexity of terminology, since although CMPA traditionally refers to immune-mediated reactions to cow's milk, it is a term encompassing numerous clinical features with different symptoms and the requirement for specific treatments. Moreover, the differential diagnosis with other very frequent diseases, especially in the first year of life, such as gastro-esophageal reflux disease or colic, is still complex. This can result in misdiagnosis and incorrect treatment, with harmful health consequences and significant economic repercussions. In this context, the combination of several omics sciences together, which have already proved useful in clarifying the allergenicity of cow's milk proteins with greater precision, could improve the diagnostic tests currently in use through the identification of new, more specific, and precise biomarkers that make it possible to improve diagnostic accuracy and predict the patient's response to the various available treatments for the recovery of tolerance.

Skin-centered strategies in food allergy prevention

While the early introduction of food allergens in the infant diet has been shown to be effective at preventing the development of food allergy (FA), its implementation in real life has been associated with various challenges. Interventions aimed at correcting skin barrier dysfunction have been explored in recent decades as a distinct or complementary mean to prevent allergic sensitization through the skin and subsequent development of FA. Studies assessing the application of emollient from birth have yielded conflicting results, and meta-analyses have demonstrated either no effect or only a slight positive effect on FA prevention. However, a careful review of the clinical trials reveals that different emollients were used, which may have explained some of the discrepancies between study results. Emollient application protocols also varied widely between studies. While firm conclusions cannot be drawn with regard to their overall efficacy at preventing FA, the available data provide valuable insight into the characteristics that could be associated with a more effective intervention. Namely, successful trials tended to use emollients with an acidic pH of 5.5, applied over the entire body, and combined with topical corticosteroids in affected areas. Consensus on the optimal strategy to restore skin barrier function could help improve the homogeneity and clinical relevance of future trials on this topic. In the meantime, clinicians should avoid products associated with worse outcomes.

Ultra-processed food intake and food allergy in children and adolescents

This study aimed to describe the dietary intake of ultra-processed foods (UPF) by children and adolescents with food allergy (FA) and to verify a possible association between the UPF intake with clinical characteristics and nutritional status in this group. This cross-sectional study included 110 children and adolescents with single or multiple FA IgE and non-IgE mediated. We evaluated food intake using the NOVA classification through the three 24-h recalls. The average contribution of UPF to total energy intake (calories) ranges from 21% in the first quartile to 43% in the last quartile (mean UPF intake 33.9 ± 14.9%). After binary logistic regression, an association was verified between dietary intake of UPF (>4th quartile) as a percentage of total energy intake and having multiple food allergies (OR 4.102; 95% CI - 1.331 to 12.643; p = .014). We concluded that children and adolescents with FA consumed a higher amount of UPF.

Characterization of Different Inflammatory Skin Conditions in a Mouse Model of DNCB-Induced Atopic Dermatitis

The mouse model of 2,4-dinitrochlorbenzene (DNCB)-induced human-like atopic dermatitis (hlAD) has been widely used to test novel treatment strategies and compounds. However, the study designs and methods are highly diverse, presenting different hlAD disease patterns that occur after sensitization and repeated challenge with DNCB on dorsal skin. In addition, there is a lack of information about the progression of the disease during the experiment and the achieved pheno- and endotypes, especially at the timepoint when therapeutic treatment is initiated. We here examine hlAD in a DNCB-induced BALB/cJRj model at different timepoints: (i) before starting treatment with dexamethasone, representing a standard drug control (day 12) and (ii) at the end of the experiment (day 22). Both timepoints display typical AD-associated characteristics: skin thickening, spongiosis, hyper- and parakeratosis, altered cytokine and gene expression, increased lipid mediator formation, barrier protein and antimicrobial peptide abnormalities, as well as lymphoid organ hypertrophy. Increased mast cell infiltration into the skin and elevated immunoglobulin E plasma concentrations indicate a type I allergy response. The DNCB-treated skin showed an extrinsic moderate sub-acute hlAD lesion at day 12 and an extrinsic mild sub-acute to chronic pheno- and endotype at day 22 with a dominating Th2 response. A dependency of the filaggrin formation and expression in correlation to the disease severity in the DNCB-treated skin was found. In conclusion, our study reveals a detailed classification of a hlAD at two timepoints with different inflammatory skin conditions and pheno- and endotypes, thereby providing a better understanding of the DNCB-induced hlAD model in BALB/cJRj mice.

Unraveling the skin; a comprehensive review of atopic dermatitis, current understanding, and approaches

Atopic dermatitis, also known as atopic eczema, is a chronic inflammatory skin disease characterized by red pruritic skin lesions, xerosis, ichthyosis, and skin pain. Among the social impacts of atopic dermatitis are difficulties and detachment in relationships and social stigmatization. Additionally, atopic dermatitis is known to cause sleep disturbance, anxiety, hyperactivity, and depression. Although the pathological process behind atopic dermatitis is not fully known, it appears to be a combination of epidermal barrier dysfunction and immune dysregulation. Skin is the largest organ of the human body which acts as a mechanical barrier to toxins and UV light and a natural barrier against water loss. Both functions face significant challenges due to atopic dermatitis. The list of factors that can potentially trigger or contribute to atopic dermatitis is extensive, ranging from genetic factors, family history, dietary choices, immune triggers, and environmental factors. Consequently, prevention, early clinical diagnosis, and effective treatment may be the only resolutions to combat this burdensome disease. Ensuring safe and targeted drug delivery to the skin layers, without reaching the systemic circulation is a promising option raised by nano-delivery systems in dermatology. In this review, we explored the current understanding and approaches of atopic dermatitis and outlined a range of the most recent therapeutics and dosage forms brought by nanotechnology. This review was conducted using PubMed, Google Scholar, and ScienceDirect databases.

The clinical burden of food allergies: Insights from the Food Allergy Research & Education (FARE) Patient Registry

Background

Food allergies are serious and potentially life-threatening, and often place a large burden on patients and their caregivers, including impacts on quality of life.

Objective

To assess the real-world patient burden of food allergies, using self-reported data available from the Food Allergy Research & Education (FARE) Patient Registry (NCT04653324).

Methods

The FARE Patient Registry is voluntary and captures real-world experiences of adults and pediatric patients in the United States, and their caregivers, through a series of surveys assessing patient health and experiences with food allergies. Self-reported data were descriptively analyzed.

Results

The FARE study cohort included 5587 patients with food allergies; 82% had multiple food allergies and 62% were aged <18 years. About half of the patients were first diagnosed by an allergist/immunologist (53%), most commonly with a skin prick test (71%) or a serum immunoglobulin E test (62%). This analysis found that food allergies (most commonly peanut [66%], tree nuts [61%], egg [43%], and milk [37%]) impart a large clinical burden on patients, many of whom experience food-related allergic reactions and comorbidities. Many patients experienced >1 food-related allergic reaction per year (42%), with 46% experiencing food-induced anaphylaxis. Half of all food-related allergic reactions occurred at home. Accidental exposures to food allergens were experienced by 77% of patients. The most common allergic comorbidities reported by patients with food allergies were atopic dermatitis (48%), asthma (46%), and allergic rhinitis (39%). The clinical burden of food allergies were found to be greater in patients with multiple food allergies, and different for adults versus pediatric patients.

Conclusion

This is the first study to assess patient experience and disease burden information from patients contributing to the FARE Patient Registry, thus providing a unique insight into the lives of patients in the United States with food allergies. These insights may assist clinicians and other public health stakeholders in the management of patients with food allergies.

Advancements in Allergen Immunotherapy for the Treatment of Atopic Dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin condition that affects individuals of all age groups, manifesting as a spectrum of symptoms varying from mild to severe. Allergen immunotherapy (AIT) involves the administration of allergen extracts and has emerged as a potential treatment strategy for modifying immune responses. Its pathogenesis involves epidermal barrier dysfunction, microbiome imbalance, immune dysregulation, and environmental factors. Existing treatment strategies encompass topical steroids to systemic agents, while AIT is under investigation as a potential immune-modifying alternative. Several studies have shown reductions in the severity scoring of atopic dermatitis (SCORAD) scores, daily rescue medication use, and visual analog scale (VAS) scores following AIT. Biomarker changes include increased IgG4 levels and decreased eosinophil counts. This review provides valuable insights for future research and clinical practice, exploring AIT as a viable option for the management of AD.

Gastrointestinal Comorbidities Associated with Atopic Dermatitis-A Narrative Review

The current understanding of atopic dermatitis (AD) seems to be extending beyond a skin-confined condition frequently associated with allergic comorbidities, as in a number of epidemiological studies, the prevalence rate of a range of illnesses has been determined to be greater in patients with AD, or inversely. In most cases, the reasons for this are vague. A subset of these conditions are gastrointestinal disorders, including food sensitization (FS) and food allergy (FA), eosinophilic esophagitis (EoE) (it is of mixed background, both IgE-dependent and independent), food protein-induced enterocolitis syndrome (FPIES) (it exemplifies an IgE-independent food allergy), Crohn's disease (CD), colitis ulcerosa (CU), celiac disease, irritable bowel syndrome (IBS), and gastroesophageal reflux disease (GERD). In this review, we performed a comprehensive search of the literature using the PubMed database. We addressed the epidemiology of the increased co-occurrence of these diseases with AD and discussed potential causes for this subject. Multiple gastroenterological comorbidities appear to be more common in patients with AD, according to our review. The mechanisms that underlie this phenomenon are largely unknown, highlighting the need for further study in this field.

Differential diagnostics of food allergy as based on provocation tests and laboratory diagnostic assays

Due to the scale of the phenomenon, food allergy constitute a significant health problem and significantly impair the quality of life of patients. Differential diagnostics, including skin tests, sIgE detection tests, basophil and mast cell activation tests as well as double-blind placebo-controlled food challenge tests, is the gold standard in the diagnosis of food allergy. Recently, increasing attention has been paid to the potential use of nasal provocation test in the diagnosis of food allergy. Allergen dose, protocol standardization, assessment of subjective complaints and objectivization of test results are important factors determining the applicability of provocation tests.

The Prevalence of Atopic Dermatitis and Food Allergy in Children Living in an Urban Agglomeration-Is There a Current Relationship?

Atopic dermatitis (AD) prevalence in Poland is more frequent in individuals who live in a city. There are more studies demonstrating that long-term exposure to air pollutants is an independent risk factor for developing AD. The aim of the study was to assess the epidemiology of AD and food allergy (FA) in school children and adolescents living in Krakow, and to find a potential relationship between the incidence of atopic dermatitis with exposure to polluted air. In this paper, we presented the incidence of AD and FA between 2014 and 2018. We analyzed data collected from nearly 30,000 children aged 7-8 and adolescents aged 16-17 from the population of children and youth in Krakow. We correlated it with annual mean concentrations of PM10 and PM2.5, which indicated a gradual improvement in the air quality in Krakow. As our research results show that the prevalence of atopic dermatitis decreased with food allergy prevalence depending on the age group. We can suspect that this is the result of children growing out of a food allergy. It may be also influenced by more consequential eating habits in a group of adolescents and the elimination of allergenic foods from the diet. The decreasing incidence of atopic dermatitis appears to be also related to improvement in air quality.

Prenatal polyunsaturated fatty acids and atopic dermatitis and food allergy in children from Polish Mother and Child Cohort study

OBJECTIVES

Polyunsaturated fatty acids (PUFAs) are involved both in immune system regulation and inflammation. The aim of this prospective study was to evaluate the association between maternal dietary intake of PUFAs during pregnancy and atopic dermatitis (AD) and food allergy (FA) in their children up to 7-9 years of age.

MATERIAL AND METHODS

The study population consists of 557 mother-child pairs from the Polish Mother and Child Cohort (REPRO_PL). Based on the Food Frequency Questionnaire completed between the 20-24th weeks of pregnancy, n-3 and n-6 PUFAs as well as n-6:n-3 fatty acid ratio were estimated using food composition tables. Children's health examinations at the age of 1, 2, and 7-9 years were performed by an allergist. Generalized estimating equations were performed in order to assess the prevalence of AD and FA at 3 time points. Independent variables in the equation were n-3, n-6 PUFAs and n-6:n-3 PUFAs ratio. In addition multivariate models were performed to assess the association of PUFAs with AD and FA.

RESULTS

The prevalence of AD was 37%, 26% and 21% and FA 26%, 22% and 22% at age of 1, 2 and 7-9 years, respectively. Higher n-6:n-3 fatty acid ratio correlated with higher prevalence of AD at age of 7-9 years (p < 0.07). In multivariate model n-6 PUFAs were significantly associated with increased risk of persistent FA (OR = 1.5, 95% CI: 1.1-2.1).

CONCLUSIONS

These results may contribute to the existing knowledge on the impact of maternal diet during pregnancy on children's optimal health, however further studies are needed before drawing conclusions and creating clinical practice guidelines. Int J Occup Med Environ Health. 2023;36(3):428-36.

The immunological and structural epidermal barrier dysfunction and skin microbiome in atopic dermatitis-an update

Atopic dermatitis (AD) is a common, chronic and relapsing inflammatory skin disease with various clinical presentations and combinations of symptoms. The pathophysiology of AD is complex and multifactorial. There are several factors involved in the etiopathogenesis of AD including structural and immunological epidermal barrier defect, imbalance of the skin microbiome, genetic background and environmental factors. Alterations in structural proteins, lipids, proteases, and their inhibitors, lead to the impairment of the stratum corneum which is associated with the increased skin penetration and transepidermal water loss. The elevated serum immunoglobulin E levels and blood eosinophilia have been shown in the majority of AD patients. Type 2 T-helper cell immune pathway with increased expression of interleukin (IL)-4, IL-5, and IL-13, has an important role in the etiopathogenesis of AD. Both T cells and keratinocytes contribute to epidermal barrier impairment in AD via a dynamic interaction of cytokines and chemokines. The skin microbiome is another factor of relevance in the etiopathogenesis of AD. It has been shown that during AD flares, Staphylococcus aureus (S. aureus) colonization increased, while Staphylococcus epidermidis (S. epidermidis) decreased. On the contrary, S. epidermidis and species of Streptococcus, Corynebacterium and Propionibacterium increased during the remision phases. However, it is not clear whether skin dysbiosis is one of the symptoms or one of the causes of AD. There are several therapeutic options, targeting these pathways which play a critical role in the etiopathogenesis of AD. Although topical steroids are the mainstay of the treatment of AD, new biological therapies including IL-4, IL-13, and IL-31 inhibitors, as well as Janus kinase inhibitors (JAKi), increasingly gain more importance with new advances in the therapy of AD. In this review, we summarize the role of immunological and structural epidermal barrier dysfunction, immune abnormalities, impairment of lipids, filaggrin mutation and skin microbiome in the etiopathogenesis of AD, as well as the therapeutic options for AD and their effects on these abnormalities in AD skin.

The Impact of Infant Feeding Regimen on Cow's Milk Protein Allergy, Atopic Dermatitis and Growth in High-Risk Infants during the First 6 Months of Life: The Allergy Reduction Trial

The development of early-onset cow's milk protein allergy and atopic dermatitis during the first months of life is multifactorial, including both genetic and nutritional aspects. This study aims to assess the impact of different feeding patterns on the incidence of cow's milk protein allergy, atopic dermatitis, and growth among infants with a family history of allergy. A total of 551 high-risk infants were randomly recruited from 3 European countries in three feeding regimens: exclusive breastfeeding, partially hydrolyzed formula, or standard formula with intact protein either exclusively or supplementary to breastfeeding. During the first 6 months of intervention, amongst infants with a family history of atopic dermatitis, 6.5% of partially hydrolyzed formula-fed infants and 22.7% of exclusively breastfed infants (p = 0.007) presented with atopic dermatitis respectively. Growth as assessed by weight increase did not differ between the aforementioned groups. Although cow's milk protein allergy was not related to the different milk feeding regimens in the whole cohort, when adjusting for high breast milk intake, the respective incident was significantly lower in the infants consuming partially hydrolyzed formula (p < 0.001). This data indicates that a specific partially hydrolyzed formula could serve as a more appropriate complement to breast milk compared to a standard intact protein formula in high-risk infants, to reduce the incidence of atopic dermatitis.

The hen and the egg question in atopic dermatitis: allergy or eczema comes first

Atopic dermatitis (AD) as a chronic inflammatory systemic condition is far more than skin deep. Co-morbidities such as asthma and allergic rhinitis as well as the psychological impact influence seriously the quality of life of the patients. Recent studies have shown that only 10% of atopic patients undergo full manifestation of the atopic march, while 40% demonstrate concomitant food allergy. Exposure to food allergens in the environment causes sensitization and food allergy through the disruption of the skin barrier, as in AD. Food allergy and AD are closely related. While not all AD patients have a food allergy, 20-40% of children with moderate to severe AD will have an IgE-mediated food allergy. It is known that they may coexist but it is unclear if food allergy worsens the course of AD. Experimental, clinical, and epidemiological studies have provided evidence of the primary role of an epidermal barrier defect in the development of sensitization to environmental allergens and that this process occurs in the damaged skin barrier rather than the gastrointestinal or respiratory tract. There is strong evidence for a connection between early AD onset and the development of other allergic diseases later in life.

Environmental Exposures may Hold the Key; Impact of Air Pollution, Greenness, and Rural/Farm Lifestyle on Allergic Outcomes

PURPOSE OF REVIEW

There has been an increased prevalence of allergy. Due to this relatively rapid rise, changes in environmental exposures are likely the main contributor. In this review, we highlight literature from the last 3 years pertaining to the role of air pollution, greenness, and the rural/farm lifestyle and their association with the development of allergic sensitization, atopic dermatitis, food allergy, and allergic rhinitis in infancy and childhood. Because asthma has a more complex pathophysiology, it was excluded from this review.

RECENT FINDINGS

Recent studies support a role for air pollution, greenness, and rural/farming lifestyle influencing atopic outcomes that continue to be defined. While many studies have examined singular environmental exposures, the interconnectedness of these exposures and others points to a need for future work to consider an individual's whole exposure. Environmental exposures' influence on atopic disease development remains an ongoing and important area of study.