Increased prevalence of airway reactivity in children with eosinophilic esophagitis

Exploring the Impact of Gender on the Characteristics and Complications of Eosinophilic Esophagitis

Background

Eosinophilic esophagitis (EoE) is a chronic inflammatory process of the esophagus often associated with structural and motility problems. Previous studies have shown an increased prevalence in males over females, however there is little data exploring the risk of esophageal complications among genders, which may be indicative of differences in disease severity.

Methods

This is a retrospective cohort study using National Inpatient Sample data including adults hospitalized between 2016 and 2020 presenting with EoE. The primary outcome measured was inpatient complications related to the patient's history of EoE and secondary outcomes include demographics, comorbidities, month of presentation, and age of patients.

Results

Of the 21 755 patients with history of EoE, 112 260 (52%) were male and 10 495 (48%) were female. Males had higher rates of several EoE complications, including esophageal obstruction, food bolus, esophageal rupture, requiring esophageal dilation, requiring esophageal laceration repair with p < 0.05 for all. Higher rates of females with EoE were seen in the Black population (p < 0.05). We also found that males were most likely to have esophageal impaction and esophageal rupture in the month of March (p < 0.05). Esophageal impaction was more common in males ages 25-29 (p < 0.05), whereas females were more likely from age 75-79 (p < 0.05).

Conclusion

Males have an overall high rate of complication from EoE. There was a higher prevalence of females with EoE in the Black population although the rates of complication remained higher in males in this subpopulation. The month of March carries a risk of esophageal impaction and rupture pronounced particularly in men. Age also appears to have an influence on the rate of esophageal impaction.

Exposures and coexisting conditions in pediatric nodular tracheobronchitis

BACKGROUND

The aim of our study was to investigate the prevalence of coexisting conditions and exposures in children with nodular tracheobronchitis diagnosed by flexible bronchoscopy.

METHODS

We conducted a single-center retrospective review of 100 children diagnosed with nodular tracheobronchitis by flexible bronchoscopy between 2012 and 2023.

RESULTS

Common coexisting diagnoses included gastroesophageal reflux disease (GERD, 50%), dysphagia/aspiration (40%), asthma (30%), recurrent croup (30%), tracheostomy dependence (19%) and eosinophilic esophagitis (EOE) (12%). Bronchoalveolar lavage (BAL) demonstrated cellular inflammation with elevated proportions of neutrophils in 63%, and lymphocytes in 24%. Among 88 patients in whom bacterial cultures were performed, 52% were positive, with Moraxella, Haemophilus, Streptococcal and Pseudomonas species predominating. Among 30 patients who underwent viral testing, 57% were positive, with rhinovirus (82%) and adenovirus (29%) predominating. Patients with neutrophilic inflammation were more likely to have a positive respiratory bacterial culture and/or viral polymerase chain reaction (p = 0.003, 0.005). Evaluation of the gastrointestinal tract included 79 patients with a history of esophagogastroduodenoscopy, 45 patients with a videofluoroscopic swallow study (VFSS), and 45 patients with multi-channel intraluminal impedance and pH testing. The majority of VFSS were abnormal (60%) demonstrating either laryngeal penetration (33%) or intratracheal aspiration (27%). Median pH reflux and impedance proximal reflux indices were 3.8% and 0.5% respectively.

CONCLUSION

Potential contributing factors in the pathophysiology of nodular tracheobronchitis include bacterial and viral infections, GERD, dysphagia/aspiration, and EOE. When nodular tracheobronchitis is observed during bronchoscopy, further evaluation to assess for these conditions should be considered.

Associations of Eosinophilic Gastrointestinal Disorders with Other Gastrointestinal and Allergic Diseases

Eosinophilic gastrointestinal disorders (EGIDs) are becoming more common causing significant suffering and reduced quality of life. These conditions can affect different parts of the digestive system, either individually or in combination. Recognition of their link to allergic disorders or other gastrointestinal (GI) diseases has raised questions about their shared underlying mechanisms, which has had implications for diagnosis and management. The authors critically examine the current understanding of the connection between EGIDs and allergic conditions (ie, atopic dermatitis, allergic rhinitis, asthma, and food allergy) and GI diseases (ie, inflammatory bowel disease, celiac disease, gastroesophageal reflux disease, and motility disorders).

Pathophysiology of Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic, progressive immune-mediated disease associated with antigen-driven type 2 inflammation and symptoms of esophageal dysfunction. Research over the last 2 decades has dramatically furthered our understanding of the complex interplay between genetics, environmental exposures, and cellular and molecular interactions involved in EoE. This review provides an overview of our current understanding of EoE pathogenesis.

Identification of CXC Chemokine Receptor 2 (CXCR2) as a Novel Eosinophils-Independent Diagnostic Biomarker of Pediatric Eosinophilic Esophagitis by Integrated Bioinformatic and Machine-Learning Analysis

Background

Eosinophilic esophagitis (EoE) is a complex allergic condition frequently accompanied by various atopic comorbidities in children, which significantly affects their life qualities. Therefore, this study aimed to evaluate pivotal molecular markers that may facilitate the diagnosis of EoE in pediatric patients.

Methods

Three available EoE-associated gene expression datasets in children: GSE184182, GSE 197702, GSE55794, along with GSE173895 were downloaded from the GEO database. Differentially expressed genes (DEGs) identified by "limma" were intersected with key module genes identified by weighted gene co-expression network analysis (WGCNA), and the shared genes went through functional enrichment analysis. The protein-protein interaction (PPI) network and the machine learning algorithms: least absolute shrinkage and selection operator (LASSO), random forest (RF), and XGBoost were used to reveal candidate diagnostic markers for EoE. The receiver operating characteristic (ROC) curve showed the efficacy of differential diagnosis of this marker, along with online databases predicting its molecular regulatory network. Finally, we performed gene set enrichment analysis (GSEA) and assessed immune cell infiltration of EoE/control samples by using the CIBERSORT algorithm. The correlations between the key diagnostic biomarker and immune cells were also investigated.

Results

The intersection of 936 DEGs and 1446 key module genes in EoE generated 567 genes, which were primarily enriched in immune regulation. Following the construction of the PPI network and filtration by machine learning, CXCR2 served as a potential diagnostic biomarker of pediatric EoE with a perfect diagnostic efficacy (AUC = ~1.00) in regional tissue/peripheral whole blood samples. Multiple infiltrated immune cells were observed to participate in disrupting the homeostasis of esophageal epithelium to varying degrees.

Conclusion

The immune-correlated CXCR2 gene was proved to be a promising diagnostic indicator for EoE, and dysregulated regulatory T cells (Tregs)/neutrophils might play a crucial role in the pathogenesis of EoE in children.

Multilevel Analysis of Racial and Ethnic Disparities in COVID-19 Hospitalization among Children with Allergies

Rationale: Previous studies have identified risk factors for coronavirus disease (COVID-19) hospitalization in children. However, these studies have been limited in their ability to disentangle the contribution of racial disparities, allergic comorbidities, and environmental exposures to the development of severe COVID-19 in at-risk children with allergies. Objectives: To examine racial and ethnic disparities in COVID-19 hospitalization and their links to potentially underlying allergic comorbidities and individual and place-based factors in children with allergies. Methods: This is an electronic health record-based retrospective study of children in 2020. The outcome was COVID-19 hospitalization categorized as no hospital care for patients with asymptomatic/mild illness, short stay for patients admitted and discharged within 24 hours, and prolonged stay for patients requiring additional time to discharge (more than 24 h). Mixed-effects and mediation models were used to determine relationships among independent variables, mediators, and COVID-19 hospitalization. Results: Among the 5,258 children with COVID-19 positive test or diagnosis, 10% required a short stay, and 3.7% required a prolonged stay. Black and Hispanic children had higher odds of longer stays than non-Hispanic White children (both P < 0.001). Children with obesity and eosinophilic esophagitis diagnoses had higher odds of short and prolonged stay (all P < 0.05). Area-level deprivation was associated with short stay (adjusted odds ratio [AOR], 15.49; 95% confidence interval [CI], 5.16-45.47 for every 0.1-unit increase) and prolonged stay (AOR, 11.82; 95% CI, 2.25-62.01 for every 0.1-unit increase). Associations between race/ethnicity and COVID-19 hospitalization were primarily mediated by insurance and area-level deprivation, altogether accounting for 99% of the variation in COVID-19 hospitalization. Conclusions: There were racial and ethnic differences in children with allergies and individual and place-based factors related to COVID-19 hospitalization. Differences were primarily mediated by insurance and area-level deprivation, altogether accounting for 99% of the variation in COVID-19 hospitalization. A better understanding of COVID-related morbidity in children and the link to place-based factors is key to developing prevention strategies capable of equitably improving outcomes.

Pediatric eosinophilic esophagitis: a review for the clinician

Eosinophilic esophagitis (EoE) is a chronic clinical-pathologic disease characterized by eosinophilic infiltration of the esophageal epithelium with esophageal dysfunction symptoms.EoE can occur at any age and has different clinical manifestations depending on the age onset.To date, esophago-gastroduodenal endoscopy (EGD) with biopsy is the gold-standard for EoE diagnosis.According to the recent consensus guidelines, proton pump inhibitors, corticosteroids and elimination diets could be a first-line therapy option. The aim of the treatment is clinical and histological remission for preventing long-lasting untreatable fibrosis.A multidisciplinary approach (allergist, gastroenterology, dietitian, and pathologist) is recommended for managing patients affected by EoE, given the complexity of its treatment.This review will provide a practical guide to assist pediatricians treating children with EoE.Moreover, it highlights the unmet needs in diagnosis and treatment that require urgent attention from the scientific community in the aim of improving the management of patients with EoE.

Microneedles for painless transdermal immunotherapeutic applications

Immunotherapy has recently garnered plenty of attention to improve the clinical outcomes in the treatment of various diseases. However, owing to the dynamic nature of the immune system, this approach has often been challenged by concerns regarding the lack of adequate long-term responses in patients. The development of microneedles (MNs) has resulted in the improvement and expansion of immuno-reprogramming strategies due to the housing of high accumulation of dendritic cells, macrophages, lymphocytes, and mast cells in the dermis layer of the skin. In addition, MNs possess many outstanding properties, such as the ability for the painless traverse of the stratum corneum, minimal invasiveness, facile fabrication, excellent biocompatibility, convenient administration, and bypassing the first pass metabolism that allows direct translocation of therapeutics into the systematic circulation. These advantages make MNs excellent candidates for the delivery of immunological biomolecules to the dermal antigen-presenting cells in the skin with the aim of vaccinating or treating different diseases, such as cancer and autoimmune disorders, with minimal invasiveness and side effects. This review discusses the recent advances in engineered MNs and tackles limitations relevant to traditional immunotherapy of various hard-to-treat diseases.

Fibroblast growth factor-2 and interleukin-4 synergistically induce eotaxin-1 expression in adipose tissue-derived stromal cells

The relationships between eosinophils and adipose tissues are involved in metabolic homeostasis. Eotaxin is a chemokine with potent effects on eosinophil migration. To clarify the mechanisms of eotaxin expression in adipose tissues, we examined the effects of fibroblast growth factor-2 (FGF-2) and interleukin-4 (IL-4) stimulation on eotaxin expression in adipose tissue-derived stromal cells (ASCs), a type of adipocyte progenitor, in vitro. ASCs expressed eotaxin-1 and did not express eotaxin-2 or -3. Eotaxin-1 expression was increased in a concentration-dependent manner following FGF-2 treatment. Additionally, ASCs expressed FGF receptor-1 (FGFR-1) and did not express FGFR-2, -3, or -4. Eotaxin-1 expression was inhibited in cells treated with the FGFR tyrosine kinase inhibitor and extracellular signal-regulated kinase (ERK) inhibitor U0126, even in the presence of FGF-2. Moreover, eotaxin-1 expression was synergistically enhanced by combined treatment with FGF-2 and IL-4 and inhibited in the presence of U0126. Eotaxin-1 expression induced by FGF-2 and IL-4 was involved in ERK activation via FGFR-1 in ASCs. Upregulation of eotaxin expression in adipose tissues could increase eosinophil migration, thereby inducing IL-4 secretion and activation of alternative macrophages and improving glucose homeostasis. These findings provide insights into the mechanisms through which eotaxin mediates metabolic homeostasis in adipose tissues and eosinophils.

Epithelial origin of eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a chronic, allergen-driven inflammatory disease of the esophagus characterized predominantly by eosinophilic inflammation, leading to esophageal dysfunction. Converging data have placed the esophageal epithelium at the center of disease pathogenesis. In particular, the main EoE disease susceptibility loci at 2p23 and 5p22 encode for gene products that are produced by the esophageal epithelium: the intracellular protease calpain 14 and thymic stromal lymphopoietin, respectively. Furthermore, genetic and functional data establish a primary role for impaired epithelial barrier function in disease susceptibility and pathoetiology. Additionally, the EoE transcriptome, a set of genes dysregulated in the esophagi of patients with EoE, is enriched in genes that encode for proteins involved in esophageal epithelial cell differentiation. This transcriptome has a high proportion of esophagus-specific epithelial genes that are notable for the unexpected enrichment in genes encoding for proteases and protease inhibitors, as well as in IL-1 family genes, demonstrating a previously unappreciated role for innate immunity responses in the esophagus under homeostatic conditions. Among these pathways, basal production of the serine protease inhibitor, Kazal-type 7 (SPINK7) has been demonstrated to be part of the normal differentiation program of esophageal epithelium. Profound lost expression of SPINK7 occurs in patients with EoE and is sufficient for unleashing increased proteolytic activity (including urokinase plasminogen activator), impaired barrier function, and production of large quantities of proinflammatory and proallergic cytokines, including thymic stromal lymphopoietin. Collectively, we put forth a model in which the esophagus is normally equipped as an anti-inflammatory sensing organ and that defects in this pathway, mediated by epithelial protease/protease inhibitor imbalances, unleash inflammatory responses resulting in disorders, such as EoE.

Risk Factors and Treatment Outcomes for Oral Immunotherapy-Induced Gastrointestinal Symptoms and Eosinophilic Responses (OITIGER)

BACKGROUND

We recently described that oral immunotherapy (OIT)-induced gastrointestinal symptoms were associated with peripheral eosinophilic responses (termed OITIGER).

OBJECTIVE

To identify treatment outcomes after dose modification and risk factors for developing OITIGER.

METHODS

Treatment modifications in patients with OITIGER (n = 65) including cumulative dose reductions or treatment suspension were individualized and based on the severity of symptoms and an associated absolute eosinophil count (AEC, eosinophils/μL) of more than 900. Multivariate analysis for risk factors associated with OITIGER was performed in milk-OIT subjects.

RESULTS

Treatment modifications reduced the cumulative daily dosage load by a median of 50% (interquartile range, 50%-67%) in 43 of 65 (66.1%) patients, deferred dose increases in 2 of 65 (3.1%) patients, or temporarily suspended treatment in 18 of 65 (27.7%) patients. Two patients (3.1%) had no treatment intervention. Symptoms and eosinophilia abated on dosage modification, allowing for resumption of dose increases (n = 34) or reinitiation of treatment (n = 9) after a median of 29 (interquartile range, 20-56) and 19 (interquartile range, 17-44) days, respectively. OITIGER reoccurred during treatment in 10 of 54 (18.5%) patients, which resolved after further dose modification. In long-term follow-up (>3-26 months), 31 of 32 patients were asymptomatic with stable AECs. Patients with OITIGER had a higher OIT failure rate (P = .004) and were less likely to reach full desensitization (P < .001), as compared with asymptomatic patients (n = 684). Multivariate analysis identified several risk factors for OITIGER: starting dose more than 120 mg (P < .001; odds ratio, 7.14), second-month dose more than 4-fold over the starting dose (P = .037; odds ratio, 2.18), and baseline AEC more than 600/μL (P = .002; odds ratio, 3.2).

CONCLUSIONS

OITIGER is transient or reversible in most subjects, and its occurrence is related to OIT starting dose, its rate of increase, and baseline AECs.

Eosinophilic esophagitis incidence in New Zealand: high but not increasing

Background and aim

Eosinophilic esophagitis (EoE) is an immune-mediated inflammatory condition of the esophagus. Recent literature has shown an increasing incidence of the disease. However, no epidemiological data exist regarding New Zealand rates of EoE. The disease is associated with atopy, and New Zealand's high rate of atopic disease means the disease may be important in our population. We carried out a retrospective study to describe the incidence of EoE in the Wellington region of New Zealand, as well as key histological and clinical factors associated with the disease.

Method

A search was made of laboratory and endoscopic databases in the Wellington region to identify all diagnosed cases in the five years between January 1, 2011, and December 31, 2015. Case notes were examined to determine the key demographic and clinical parameters in the cases. Incidence rates were calculated for each year, and the effects of age group and sex on the incidence rates were analyzed.

Result

We found 152 cases of EoE in the Wellington region with an annual incidence of 6.95 per 100,000 person/years. We found no evidence of a significant difference in incidence rates by year in our study population. There was a significantly lower incidence rate in those aged <16 compared to those aged ≥16 (RR=0.26). Males had a higher incidence rate than females with an estimated rate ratio of 2.45 (p<0.05).

Conclusion

Our results are in contrast to previous reports of increasing incidence rates and may reflect a leveling off of incidence. Further research is needed to determine whether the low incidence in our pediatric age group is due to ascertainment bias or due to a real difference in the epidemiology of EoE in NZ compared to other countries.

Gastrointestinal Dysmotility and the Implications for Respiratory Disease

Purpose of the review

Gastroesophageal reflux disease (GERD) is frequently implicated as a cause for respiratory disease. However, there is growing evidence that upper gastrointestinal dysmotility may play a significantly larger role in genesis of respiratory symptoms and development of underlying pulmonary pathology. This paper will discuss the differential diagnosis for esophageal and gastric dysmotility in aerodigestive patients and will review the key diagnostic and therapeutic interventions for this dysmotility.

Recent findings

Previous studies have shown an association between GERD and pulmonary pathology in children with aerodigestive disorders. Recent publications have demonstrated the presence of esophageal and gastric dysfunction, using fluoroscopic and nuclear medicine studies, in aerodigestive patients who commonly present to pulmonary and otolaryngology clinics. High-resolution impedance manometry (HRIM) has revolutionized our understanding of esophageal dysmotility and its role in pathogenesis of aspiration and esophageal dysfunction and subsequent respiratory compromise.

Summary

Esophageal and gastric dysmotility have a profound effect on development of respiratory symptoms and pulmonary sequalae in aerodigestive patients. However, our understanding of the pathophysiology is in its infancy. Prospective studies in are needed to address key clinical questions such as: What degree of dysmotility initiates respiratory compromise? What diagnostic tests and therapeutic options best predict aerodigestive outcomes?

Non-IgE-mediated gastrointestinal allergies-Do they have a place in a new model of the Allergic March

The rise in food allergy has been described as the "second wave" of the allergy epidemic, with some developed countries reporting a prevalence of 10% of challenge-proven food allergies. Recognition of the Allergic March has played a crucial role in identifying causality in allergic conditions, linking atopic dermatitis to food allergy and food allergy to other atopic disorders, thereby highlighting opportunities in prevention and the importance of early intervention. This publication will establish the value of weaving the less well-understood, non-IgE-mediated food allergy into the Allergic March and mapping its progression through childhood and its associated co-morbidities. The proposed non-IgE-mediated Allergic March highlights the concomitant presentation of gastrointestinal symptoms and atopic dermatitis as early presenting symptoms in confirmed non-IgE-mediated allergies and the later development of atopic co-morbidities, including asthma and allergic rhinitis, similar to the IgE-mediated Allergic March. This publication highlights recent observations of a link between non-IgE-mediated food allergy in early childhood and functional gastrointestinal disorders in later life and also the reported occurrence of extra-intestinal manifestations at later ages. Although significant limitations exist in regard to the proposed evolution of the Allergic March model, the authors hope that this publication will influence the management of non-IgE-mediated gastrointestinal allergies and inform future research and interventions.

Eosinophilic Esophagitis: an Important Comorbid Condition of Asthma?

Eosinophilic esophagitis and asthma are frequently found as comorbid conditions in children and adults along with other manifestations of atopic diathesis. These two conditions have similar T helper 2 responses-driven pathophysiology and share common management strategies such as using systemic corticosteroids and targeted anti-cytokine biologic therapies. Review of the literature finds that asthma is often a comorbid condition in eosinophilic esophagitis in both children and adults; however, the EoE-asthma relationship remains poorly characterized mechanistically and clinically. EoE and asthma commonly share several comorbid conditions such as allergic rhinitis and gastroesophageal reflux disease; therefore, addressing these comorbid conditions has the potential to improve and/or maintain control in both diseases. Similar to asthma, patients with EoE frequently demonstrate elevations in serum markers of atopy, including serum IgE levels, peripheral eosinophil counts, and T helper 2-related cytokines. Gastroesophageal reflux disease is thought to affect asthma through microaspirations, airway hyperresponsiveness, and increased vagal tone. The understanding of the relationship between gastroesophageal reflux and EoE is still evolving but seems to be bidirectional and interactive. In terms of treatment, similar classes of medications have been used in both EoE and asthma. In both children and adults, EoE remission can be achieved by food trigger avoidance and use of corticosteroids and biologic therapies. Asthma control is mostly achieved through inhaled corticosteroids, and long but biologic therapies are increasingly used in severe subsets of the disease. Significant clinical and mechanistic work needs to be accomplished to better understand the relationship between asthma, EoE, and their interaction with other allergic diseases. Understanding whether shared mechanisms exist can lead to the development of new diagnostic and therapeutic strategies. The following review examines the existing literature regarding prevalence, common comorbidities, and potential therapeutic approach and identifies gaps in knowledge and future directions.

Minimally invasive biomarker studies in eosinophilic esophagitis: A systematic review

BACKGROUND

Eosinophilic esophagitis (EoE) is a chronic, inflammatory disease of the esophagus that currently requires repeated endoscopic biopsies for diagnosis and monitoring because no reliable noninvasive markers have been identified.

OBJECTIVE

To identify promising minimally invasive EoE biomarkers and remaining gaps in biomarker validation.

METHODS

We performed a systematic review of EMBASE, Ovid MEDLINE, PubMed, and Web of Science from inception to June 6, 2017. Studies were included if patients met the 2007 consensus criteria for EoE diagnosis, a minimally invasive biomarker was assessed, and the study included at least 1 control for comparison.

RESULTS

The search identified 2094 studies, with 234 reviewed at full-text level, and 49 included in the analysis (20 adult, 19 pediatric, 7 pediatric and adult, and 3 not stated). Most (26 of 49) were published after 2014. Thirty-five studies included healthy controls, 9 analyzed atopic controls, and 29 compared samples from patients with active and inactive EoE. Minimally invasive biomarkers were obtained from peripheral blood (n = 41 studies), sponge or string samples (n = 3), oral or throat swab secretions (n = 2), breath condensate (n = 2), stool (n = 2), and urine (n = 2). The most commonly reported biomarkers were peripheral blood eosinophils (n = 16), blood and string eosinophil granule proteins (n = 14), and eosinophil surface or intracellular markers (n = 12). EoE biomarkers distinguished active EoE from healthy controls in 23 studies, atopic controls in 2 studies, and inactive EoE controls in 20 studies.

CONCLUSION

Several promising minimally invasive biomarkers for EoE have emerged; however, few are able to differentiate EoE from other atopic diseases.

Gastroesophageal Reflux Disease and Aerodigestive Disorders

This relationship between gastroesophageal reflux and airway disorders is complex, possibly bidirectional, and not clearly defined. The tools used to investigate gastroesophageal reflux are mostly informative about involvement of gastroesophageal reflux within the gastrointestinal tract, although they are often utilized to study the relationship between gastroesophageal reflux and airway issues with are suspected to occur in relation to reflux. These modalities often lack specificity for reflux-related airway disorders. Co-incidence of gastroesophageal reflux and airway disorders does not necessarily infer causality. While much of our focus has been on managing acidity, controlling refluxate is an area that has not been traditionally aggressively pursued. Our management approach is based on some of the evidence presented, but also often from a lack of adequate study to provide further guidance.

Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic allergic inflammatory disease of the esophagus that effects children and adults. Typical symptoms of EoE typically involve failure to thrive and vomiting in small children, and dysphagia and food impaction in adolescents and adults. However, throat clearing, choking, gagging, and hoarseness have also been observed and these issues often bring patients to first seek otolaryngology and pulmonary evaluation. Diagnosis is only made by esophogastroduodenoscopy with biopsy, so clinicians must have a low threshold for considering eosinophilic esophagitis even in the absence of frank gastrointestinal symptoms.

Pathophysiology of Eosinophilic Esophagitis

Eosinophilic esophagitis is an emerging disease that is distinguished from gastroesophageal reflux disease by the expression of a unique esophageal transcriptome and the interplay of early life environmental factors with distinct genetic susceptibility elements at 5q22 (TSLP) and 2p23 (CAPN14). Rare genetic syndromes have uncovered the contribution of barrier disruption, mediated in part by defective desmosomes and dysregulated transforming growth factor beta production and signaling, to eosinophilic esophagitis pathophysiology. Experimental modeling has defined a cooperative role of activated eosinophils, mast cells, and the cytokines IL-5 and IL-13, mediated by allergic sensitization to multiple foods. Understanding these processes is opening the way to better treatment based on disrupting allergic inflammatory and type 2 cytokine-mediated responses, including anti-cytokine therapeutics and dietary therapy.