Seasonal distribution of initial diagnosis and clinical recrudescence of eosinophilic esophagitis: a systematic review and meta-analysis

Efficacy of Dietary Therapy for Eosinophilic Esophagitis in Children and Adults: An Updated Systematic Review and Meta-Analysis

BACKGROUND

Several dietary approaches have been used to induce remission in patients with eosinophilic esophagitis (EoE), yielding varied results.

METHODS

We searched the MEDLINE, EMBASE, and Scopus databases up to May 2024 to identify studies including dietary interventions for EoE used as monotherapy. Summary estimates with 95% CIs for achieving <15 eosinophils/HPF were calculated for each approach. Fixed or random effects models were used depending on heterogeneity (I2); publication bias risks were assessed using funnel plot analyses. Subgroup analyses results were compared using meta-regression.

RESULTS

Forty-three studies with 2825 patients were included in quantitative summaries. The overall rate of histologic remission was 60.6% (95% CI, 54.6-66.5%). Effectiveness rates were 94.5% (95% CI, 92.3-96.4%) for elemental diets, 63.9% (95% CI, 58.5-69.2%) for six-food elimination diets, 54.7% (95% CI, 45.7-63.6%) for four-food elimination diets, 44.3% (95% CI, 36.1-52.8%) for two-food elimination diets, 46.4% (95% CI, 40-52.9%) for one-food elimination diets, and 39.5% (95% CI, 30.3-49.2%) for allergy testing-directed food elimination diets. Overall, superior efficacy was noted in children than in adults and in retrospective compared to prospective studies.

CONCLUSION

Diet therapy remains an effective therapeutic asset for pediatric and adult patients with EoE, with increasing efficacy noted as the levels of dietary restriction increase.

Eosinophilic esophagitis in the era of biologics

INTRODUCTION

Eosinophilic esophagitis (EoE) is a chronic inflammatory, disabling disorder characterized by prominent eosinophilic inflammation of the esophagus, leading to troublesome symptoms including dysphagia and food impaction. The natural history of EoE is poorly known, but it may lead to esophageal strictures. The therapeutic armamentarium is expected to grow in the near future, especially due to the availability of novel biological therapies targeting crucial inflammatory pathways of EoE.

AREAS COVERED

In this review, we discuss the main clinical features and natural history of EoE, focusing on the current therapeutic strategies, as well as past and current trials investigating biologics for its treatment.

EXPERT OPINION

Dupilumab has been the first approved biologic drug for the treatment of EoE; long-term studies assessing how it could change the natural history of EoE are awaited. Novel biological drugs or other molecules are currently under study and could change the current treatment algorithms in the near future. Proper drug positioning and long term 'exit strategies' are yet to be defined.

Epidemiologic and Clinical Clues to the Etiology of Eosinophilic Esophagitis

Despite the rising prevalence and incidence of eosinophilic esophagitis (EoE), the etiology and pathophysiology remain unknown. Studies to date suggest that complex interactions between genetic and environmental risk factors result in the development and presentation of disease. Examining environmental factors both in the early life and later life exposures offers potential clues for the development of EoE, although challenges exist in making causal inferences due to diagnostic delay and access, ascertainment biases, and misclassification of cases. The authors review studies supporting early life factors as etiologic factors in the development of EoE.

Six-Food Elimination Diet Is Less Effective During Pollen Season in Adults With Eosinophilic Esophagitis Sensitized to Pollens

INTRODUCTION

The role of inhaled and swallowed aeroallergens in treatment outcomes of adult patients with eosinophilic esophagitis (EoE) is unclear. We hypothesized that the pollen season contributes to the failure of the 6-food elimination diet (SFED) in EoE.

METHODS

We compared outcomes of patients with EoE who underwent SFED during vs outside of the pollen season. Consecutive adult patients with EoE who underwent SFED and skin prick test (SPT) for birch and grass pollen were included. Individual pollen sensitization and pollen count data were analyzed to define whether each patient had been assessed during or outside of the pollen season after SFED. All patients had active EoE (≥15 eosinophils/high-power field) before SFED and adhered to the diet under the supervision of a dietitian.

RESULTS

Fifty-eight patients were included, 62.0% had positive SPT for birch and/or grass, whereas 37.9% had negative SPT. Overall, SFED response was 56.9% (95% confidence interval, 44.1%-68.8%). When stratifying response according to whether the assessment had been performed during or outside of the pollen season, patients sensitized to pollens showed significantly lower response to SFED during compared with outside of the pollen season (21.4% vs 77.3%; P = 0.003). In addition, during the pollen season, patients with pollen sensitization had significantly lower response to SFED compared with those without sensitization (21.4% vs 77.8%; P = 0.01).

DISCUSSION

Pollens may have a role in sustaining esophageal eosinophilia in sensitized adults with EoE despite avoidance of trigger foods. The SPT for pollens may identify patients less likely to respond to the diet during the pollen season.

Food allergy: cause or consequence of pediatric eosinophilic esophagitis? Potential implications of ultraprocessed foods in prevention and management

Eosinophilic esophagitis (EoE) is a chronic, immune-mediated disease characterized by eosinophilic infiltration, leading to esophageal dysfunction, inflammation, and fibrotic remodeling. In the last few decades, there has been an increased prevalence of EoE at an alarming rate in the pediatric age. The pathogenesis of EoE is still largely undefined, and this limits the definition of effective strategies for the prevention and management of this condition. EoE is considered a multifactorial disease arising from a negative interaction between environmental factors and genetic background, causing an impaired esophageal epithelial barrier with subsequent abnormal allergen exposure activating type 2 (Th2) inflammation. Food antigens have been suggested as key players in Th2 inflammation in pediatric patients with EoE, but emerging evidence suggests a potential role of other dietary factors, including ultraprocessed foods, as possible triggers for the occurrence of EoE. In this paper, we discuss the potential role of these dietary factors in the development of the disease, and we propose a new approach for the management of pediatric patients with EoE.

Impact of environmental factors on the epidemiology of eosinophilic esophagitis in southwestern Europe (2007-2020)

Background

Eosinophilic esophagitis (EoE) is a disease characterized by symptoms of esophageal dysfunction and at least 15 eosinophils/hpf in the esophagus. Other systemic and local causes of esophageal eosinophilia should be excluded.

Objectives

The study objectives were to examine the annual epidemiology of EoE for 14 consecutive years, investigate whether there is a relationship between the count of aeroallergens and the incidence of EoE for 12 years, evaluate whether there are family ties between the patients with EoE, and determine whether there are cases of EoE that are triggered or exacerbated by pollens.

Methods

We conducted a prospective, descriptive, and analytic study in patients with EoE for 14 years (2007-2020). The study variables were age, sex, relatives with EoE, time of evolution of the symptoms until diagnosis of the disease, and symptoms. We examined incidence and prevalence, annual counts of aeroallergens for 12 years, and number of diagnoses per year (in 2007-2020). We studied patients with active EoE (in April-July) and EoE in remission (in August-March) for 2 consecutive years. Exacerbations were investigated by measuring symptoms using a visual analog scale of 1 to 10.

Results

Of the 366 patients with EoE (studied from 2007 to 2020), 83.5% were atopic, with respiratory allergy and 28% had a food allergy. Their mean age was 35 years. The time of evolution of the symptoms was more than 6 years. Only 11% of the patients had a degree of kinship. Of the 366 patients, 87% had dysphagia, 27% had had impactions, and 12.5% had other symptoms of esophageal dysfunction. We found a positive correlation between the incidence of EoE and Platanaceae pollens. We did not detect any case of EoE triggered or exacerbated by pollens.

Conclusions

The epidemiology of EoE in southwestern Europe continues to grow. We have corroborated the relevant impact of the environment on genetics. Future studies will clarify the possible relevance of Platanaceae pollens in the increased epidemiology of EoE. The role of grass and Oleaceae pollens in triggering EoE is limited by having a short pollination in time.

International consensus statement on allergy and rhinology: Allergic rhinitis - 2023

BACKGROUND

In the 5 years that have passed since the publication of the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR-Allergic Rhinitis 2018), the literature has expanded substantially. The ICAR-Allergic Rhinitis 2023 update presents 144 individual topics on allergic rhinitis (AR), expanded by over 40 topics from the 2018 document. Originally presented topics from 2018 have also been reviewed and updated. The executive summary highlights key evidence-based findings and recommendation from the full document.

METHODS

ICAR-Allergic Rhinitis 2023 employed established evidence-based review with recommendation (EBRR) methodology to individually evaluate each topic. Stepwise iterative peer review and consensus was performed for each topic. The final document was then collated and includes the results of this work.

RESULTS

ICAR-Allergic Rhinitis 2023 includes 10 major content areas and 144 individual topics related to AR. For a substantial proportion of topics included, an aggregate grade of evidence is presented, which is determined by collating the levels of evidence for each available study identified in the literature. For topics in which a diagnostic or therapeutic intervention is considered, a recommendation summary is presented, which considers the aggregate grade of evidence, benefit, harm, and cost.

CONCLUSION

The ICAR-Allergic Rhinitis 2023 update provides a comprehensive evaluation of AR and the currently available evidence. It is this evidence that contributes to our current knowledge base and recommendations for patient evaluation and treatment.

Description of allergic phenotype in patients with eosinophilic oesophagitis: management protocol proposal

There is a profile of patient with eosinophilic oesophagitis and atopic background, marked by the existence of IgE-mediated sensitizations. Our aim is to report the observed sensitivities to environmental and food allergens and panallergens in patients with eosinophilic oesophagitis with atopic background as well as characterizing other markers or analytical parameters. We suspect that the prevalence of sensitization to panallergens will be high and this will probably be relevant in terms of the onset and clinical course of the disease. We collated clinical and analytical data from 160 adult patients with a reported diagnosis of eosinophilic oesophagitis. These patients were studied between 1 January 2012 and 31 December 2020. During an initial visit skin tests were performed with full batteries of routine aero-allergens and foodstuffs. Patients were subsequently referred for blood test and determination of specific IgE, blood count and total IgE (in all cases), as well as eosinophilic cation protein and IMMUNOISAC in the centres in which this was available. We were able to detect a broad spectrum of sensitizations to environmental, foodstuffs and panallergens. The most common allergic disease was rhinoconjuntivitis. The sensitizations observed to foodstuffs were atypical for the adult population and were not responsible for manifestations compatible with immediate allergy. An important percentage of patients presented seasonal worsening of choking symptoms. We should be able to identify patients with eosinophilic oesophagitis and atopic background. Identifying this phenomenon would enable giving dietary and environmental recommendations as well as more specific and effective treatments to our patients.

Nature with Nurture: the Role of Intrinsic Genetic and Extrinsic Environmental Factors on Eosinophilic Esophagitis

PURPOSE OF REVIEW

As the rising prevalence and incidence of eosinophilic esophagitis (EoE) has quickly outpaced the rate of esophageal biopsies, particularly in Westernized countries, several studies have suggested a link between intrinsic genetic and extrinsic environmental risk factors and the development, presentation, and diagnosis of EoE. This review aims to critically assess existing studies describing the role of the environment on the development, symptomatic presentation, and diagnosis of this recently recognized chronic immune-mediated disease.

RECENT FINDINGS

We present and critically evaluate the working hypotheses and supportive studies thus far on environmental factors on EoE, describe sources of potential bias in diagnosis due to socioeconomic factors and thus undermining studies of EoE etiology, and highlight opportunities for future research. As genetics alone do not explain the rapid rise of EoE, we must look to environmental, or extrinsic, factors both in the early-life period which shape the development of the gut microbiome, as well as later life contributing to diagnosis of this new disease. Future etiologic studies linking risk factors to EoE development in individual patients are needed.

Eosinophilic oesophagitis in Denmark: Population‐based incidence and prevalence in a nationwide study from 2008 to 2018

Background

Eosinophilic oesophagitis (EoE) is a chronic immune‐mediated or antigen‐mediated oesophageal disease characterised by symptoms related to oesophageal dysfunction and eosinophil‐predominant inflammation.

Objective

We aimed to estimate the incidence and prevalence of EoE in Denmark during the period 2008–2018.

Methods

Based on data from nationwide registers we identified cases of EoE using two definitions: a broad definition based solely on oesophageal biopsies registered in the Danish Pathology Register and a narrow definition also including symptoms of oesophageal dysfunction registered in the Danish National Patient Registry. The annual incidence and prevalence were standardised by sex and age in 5‐year intervals to the 2013 study population.

Results

From 2008 to 2011, the standardised incidence of EoE was stable, but from 2011 to 2018 it increased from 3.9 (95% CI 3.3–4.4) to 11.7 (95% CI 10.8–12.6) per 100,000 person‐years. Similar temporal trends were observed when using the narrow EoE definition. The increase in incidence was most pronounced in men and in individuals above 40 years of age. In children, the EoE incidence was a fourth of the incidence in adults aged 40–64 years: 4.4 (95% CI 3.2–5.6) versus 17.6 (95% CI 15.7–19.5) per 100,000 person‐years. The EoE incidence varied substantially across the five regions in Denmark. Overall, the biopsy rate as well as the proportion of oesophageal biopsies with detected eosinophilia increased during the study period.

Conclusion

This study of the entire population of Denmark during the period 2008 to 2018 shows that the incidence and prevalence of EoE is not yet plateauing and that EoE could be severely underdiagnosed, especially in children.

Characterization of Eosinophilic Esophagitis From the European Pediatric Eosinophilic Esophagitis Registry (pEEr) of ESPGHAN

OBJECTIVES

Few pediatric data on phenotypic aspects of eosinophilic esophagitis (EoE) are available. The pEEr registry was developed to prospectively characterize children with EoE from Europe and Israel.

METHODS

pEEr is an ongoing prospective registry enrolling children with esophageal eosinophilia (≥15 eos/HPF). Anonymized data were collected from 19 pediatric centers. Data regarding demographics, clinical manifestations, endoscopy, histology, and therapies were collected.

RESULTS

A total of 582 subjects (61% male) were analyzed. The median age at diagnosis was 10.5 years [interquartile range (IQR): 5.7-17.7], whereas the age at symptom onset was 9.2 years (IQR: 4.3-16.4), resulting in a median diagnostic delay of 1.2 years (IQR: 0.7-2.3). The diagnostic delay was longer below age <6 years. Shorter diagnostic delays were associated with the presence of food allergy or a family history for EoE. Symptoms varied by age with dysphagia and food impaction more common in adolescents, while vomiting and failure to thrive more common in younger children ( P < 0.001). Among endoscopic findings, esophageal rings were more common in adolescents, whereas exudates were more frequent in younger children( P < 0.001). Patients who responded to proton pump inhibitors (PPIs) were more likely to be older, males, and less often presented severe endoscopic findings. Patients unresponsive to PPIs received topical steroids (40%), elimination diet (41%), or a combined therapy (19%).

CONCLUSIONS

EoE findings vary according to age in pediatric EoE. Young children are commonly characterized by non-specific symptoms, atopic dermatitis, food allergy, and inflammatory endoscopic lesions. Adolescents usually have dysphagia or food impaction, fibrostenotic lesions, and a better PPI response.

The Role of the Environment in Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic immune-mediated disease clinicopathologically characterized by esophageal dysfunction. EoE is characterized by eosinophilic histologic inflammation indistinguishable from other atopic diseases such as asthma, eczema, or allergic rhinitis, which often co-occur in patients with EoE. This suggest a possible shared pathophysiology and triggers in the development of EoE with other atopic conditions. Although the evidence of EoE being linked to exposure to allergenic foods is strong, the connection between EoE and aeroallergens is less understood. In this review, we will discuss clinical, epidemiological, and animal studies that investigate how environmental allergens influence the clinical manifestations of EoE and its seasonality. It is also known that the developing immune system is significantly shaped by early-life exposures, pollution, climate change, and those factors that are known to influence development of asthma. We therefore also describe the evidence for and the gaps in our knowledge of the role of early-life exposures, pollution, and climate change in the development of EoE.

Rising trend in p​ediatric eosinophilic esophagitis incidence in Spain: Results of a prospective study 2014-16

OBJECTIVES

The rate of eosinophilic esophagitis (EoE) diagnosis is increasing. This study aims to determine the incidence of EoE in the pediatric population residing in the southwestern Madrid and to analyze whether absolute monthly pollen counts, modified or not by the principal atmospheric pollutants, are associated with it.

METHODS

A cross-sectional study on prospectively recruited patients was designed to calculate the incidence of EoE in children aged under 15 years who were diagnosed between September 2014 and August 2016 in twelve hospitals. We collected demographic and symptoms data, date of onset of symptoms, date of medical consultation, and date of endoscopic diagnosis of each included patient. Relative risk estimation was performed to assess the association between the incidence of diagnosis and monthly pollen counts and levels of atmospheric pollutants. All these models were adjusted for the number of total patients that underwent endoscopy at first time.

RESULTS

One hundred forty-eight patients were included. The most frequent symptoms were abdominal pain [42.57%], dysphagia [42.57%], and impaction [39%-86%]. The median overall monthly incidence was 1.13 [interquartile rank: 0.97-1.43] cases/100,000 children, and the annual mean was 15.2. The overall analysis of the relationship between incidence and absolute monthly counts, corrected for the number of first-time endoscopies performed, revealed no statistically significant association with pollen and air pollutants. There was a higher frequency of diagnosis during the pollination period of Cupressaceae [relative risk 1.647; 95% CI (1.192-2.276) p < .002] and during February and November (relative risk 1.67; p < .01).

CONCLUSIONS

This study confirms the high incidence of eosinophilic esophagitis and also suggests a period of higher incidence of diagnosis in the months of February and November as well as in the period of high pollination of Cupressaceae.

The role of the allergist in the management of eosinophilic esophagitis

PURPOSE OF REVIEW

The purpose of this review is to provide the current understanding of the role of allergens/antigens, the use of allergy testing, and to elucidate the role of the allergist in the management of eosinophilic esophagitis (EoE).

RECENT FINDINGS

EoE is a T2 immune disorder that is part of the atopic march. EoE patients commonly have multiple concurrent allergic disorders. Recent studies demonstrate that, like other allergic diseases, epithelial barrier dysfunction plays a key role in EoE pathogenesis. Aero- and food allergens have been identified as EoE triggers. EoE management includes the assessment and avoidance of its instigating antigens. Due to the integrated T2 immune response in an allergic individual, proper EoE care should include the control of underlying atopic disorders. EoE is a complex disease that is optimally managed by a multidisciplinary approach.

SUMMARY

This review provides an update on the role of the allergist in the clinical management of EoE.

Eosinophilic esophagitis-established facts and new horizons

Despite dramatic advances in our understanding of the pathogenesis and course of disease in the relatively short timeframe since the discovery and first description of eosinophilic esophagitis (EoE) less than three decades ago, many open questions remain to be elucidated. For instance, we will need to better characterize atypical clinical presentations of EoE and other forms of esophageal inflammatory conditions with often similar clinical presentations, nut fulfilling current diagnostic criteria for EoE and to determine their significance and interrelationship with genuine EoE. In addition, the interrelationship of EoE with other immune-mediated diseases remains to be clarified. Hopefully, a closer look at the role of environmental factors and their interaction with genetic susceptibility often in context of atopic predisposition may enable identifying the candidate substances/agents/allergens and potentially earlier (childhood) events to trigger the condition. It appears plausible to assume that in the end—comparable to current concepts in other immune-mediated chronic diseases, such as for instance inflammatory bowel disease or asthma bronchiale—we will not be rewarded with the identification of a “one-and-only” underlying pathogenetic trigger factor, with causal responsibility for the disease in each and every EoE patient. Rather, the relative contribution and importance of intrinsic susceptibility, i.e., patient-driven factors (genetics, aberrant immune response) and external trigger factors, such as food (or aero-) allergens as well as early childhood events (e.g., infection and exposure to antibiotics and other drugs) may substantially differ among given individuals with EoE. Accordingly, selection and treatment duration of medical therapy, success rates and extent of required restriction in dietary treatment, and the need for mechanical treatment to address strictures and stenosis require an individualized approach, tailored to each patient. With the advances of emerging treatment options, the importance of such an individualized and patient-centered assessment will increase even further.

Nutritional approach to eosinophilic esophagitis: which diet and when

Dietary elimination therapy has been for a long time an option for patients with eosinophilic esophagitis (EoE) and remains the only therapy targeting the cause of the disease. Different dietary approaches have been described along the last 3 decades, and cumulative evidence has defined the effectiveness and usefulness of each approach. Elemental diets are highly effective to induce EoE remission, but unpractical in most patients. Allergy testing-directed food restrictions resulted inefficient to induce remission in a significant proportion of patients (especially adults) and show a low concordance with the dietary causes of EoE. Empiric elimination diets are currently considered the most effective drug-free treatment for patients of all ages with EoE, after widely providing reproducible results. Highly restrictive empiric six-food elimination diets have paved the way to most efficient and less restrictive step-up approaches, which now include four-food and two-food elimination diets. The potential role of milk-elimination, especially in children, should be also considered. Multiple factors including demographics, nutritional status, patient and family lifestyles, social and financial support, and acceptance of repeated endoscopies influence the results of dietary therapy. Dietary therapy in EoE should be patient centered, and the patients and/or their families together with the medical provider should participate in the decision to set up this treatment. This article updates recent knowledge on dietary therapy for EoE and provides guideline to choose the most suitable alternative for patients with EoE, as well as practical tips to achieve the best results in clinical practice.

Epidemiology and risk factors for eosinophilic esophagitis: lessons for clinicians

INTRODUCTION

The rapid expansion in the epidemiology of eosinophilic esophagitis (EoE) is being documented, along with cumulative research assessing environmental exposures associated with EoE and susceptibility due to genetic variants.

AREAS COVERED

Incidence rates for EoE of 5-10 new cases per 100,000 inhabitants annually have shown an increase in recent reports of up to 20 in some countries; the highest prevalence being reported for Europe and North America, where EoE now affects more than 1 out of 1,000 people. EoE has been shown to be associated with several disorders, Th2-mediated atopies being the most common. Patients with EoE exhibit increased frequency of asthma, allergic rhinitis and eczema, and EoE has been considered as a late component of the atopic march. Risk variants in TSLP, CAPN14 and LRCC32 genes, among others, have all been related to EoE, and interact with prenatal and early life exposure potentially modifying abundance and composition of gut microbiome. Dysregulated interactions between bacteria and mucosal immunity emerge as leading causes of EoE.

EXPERT OPINION

The expanding epidemiology of EoE, the resources needed and subsequent increasing healthcare costs require additional effort to optimize cost-effective management and unveil mechanisms that enhance the development of future preventive strategies.

Dietary therapy for eosinophilic esophagitis: chances and limitations in the clinical practice

INTRODUCTION

Eosinophilic esophagitis (EoE) is a non-Immunoglobulin E-mediated food allergy that currently represents the main cause of dysphagia and food impaction in children and young adults. Diet remains the only therapy targeting the cause of the disease. Relevant advances in recent years allow novel approaches to dietary therapy in EoE.

AREAS COVERED

An up-to-date review on dietary therapy for EoE is provided, as a potential first-line anti-inflammatory therapy able to induce and maintain remission in a significant proportion of patients. Unpractical elemental diets and suboptimal food allergy testing-directed food restrictions paved the way for empiric elimination diets, which currently are to be considered as the most effective drug-free treatment for EoE. After largely restrictive empiric six-food elimination diets, most efficient step-up approaches now include four-food and two-food elimination diets. The potential of milk-elimination is also discussed.

EXPERT COMMENTARY

An empiric elimination diet step-up strategy should be currently considered as the initial approach for dietary treatment in EoE patients of all ages. Compared to a top-down strategy, step-up diets reduce the need for endoscopic procedures, shorten diagnostic process times, and avoid unnecessary restrictions. Furthermore, early identification of responders with few food triggers may select best candidates for maintenance dietary therapy.

The Role of the Environment in Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic, immune-mediated inflammatory disease with incompletely understood pathogenesis. Though disease manifestations were initially ascribed to a delayed reaction to food allergens, emerging evidence suggests that modifiable host factors and environmental allergen exposure may also play critical roles in the pathogenesis and ongoing manifestations of EoE. As with other atopic diseases, lack of early-life exposure to microbial pathogens leads to an immune tolerance defect and reprograms the commensal gut microflora toward a type 2 T helper (Th2) phenotype; the esophageal microbiota, a rich environment consisting of diverse bacterial species, is greatly altered by inflammation. Although multiple early life microbiome-altering factors are associated with EoE development, no causative, direct relationships have been identified. Interestingly, large, cross-sectional analyses of several populations identify an inverse relationship between Helicobacter pylori presence and EoE, likely via virulence factors that downregulate Th2 inflammation, though causality has not been proven. In regard to environmental allergens, some studies support seasonal variation in EoE diagnosis and flares, and EoE can be generated after a large, identifiable aeroallergen exposure. Examples include mouse models of intranasal Aspergillus dosing and following initiation of oral immunotherapy to foods or environmental allergens. Conversely, treatment of allergic rhinoconjunctivitis may improve EoE symptoms, though data is limited to case reports and small series. Unfortunately, biologic therapies for atopic conditions have failed to improve EoE symptoms despite improvement in esophageal eosinophil count, though dupilumab shows promise in ongoing studies. Overall, this chapter shows that EoE pathogenesis is likely multifactorial, and the environment is a key component in our understanding of EoE.

The Role of the Environment in Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic, immune-mediated inflammatory disease with incompletely understood pathogenesis. Though disease manifestations were initially ascribed to a delayed reaction to food allergens, emerging evidence suggests that modifiable host factors and environmental allergen exposure may also play critical roles in the pathogenesis and ongoing manifestations of EoE. As with other atopic diseases, lack of early-life exposure to microbial pathogens leads to an immune tolerance defect and reprograms the commensal gut microflora toward a type 2 T helper (Th2) phenotype; the esophageal microbiota, a rich environment consisting of diverse bacterial species, is greatly altered by inflammation. Although multiple early life microbiome-altering factors are associated with EoE development, no causative, direct relationships have been identified. Interestingly, large, cross-sectional analyses of several populations identify an inverse relationship between Helicobacter pylori presence and EoE, likely via virulence factors that downregulate Th2 inflammation, though causality has not been proven. In regard to environmental allergens, some studies support seasonal variation in EoE diagnosis and flares, and EoE can be generated after a large, identifiable aeroallergen exposure. Examples include mouse models of intranasal Aspergillus dosing and following initiation of oral immunotherapy to foods or environmental allergens. Conversely, treatment of allergic rhinoconjunctivitis may improve EoE symptoms, though data is limited to case reports and small series. Unfortunately, biologic therapies for atopic conditions have failed to improve EoE symptoms despite improvement in esophageal eosinophil count, though dupilumab shows promise in ongoing studies. Overall, this chapter shows that EoE pathogenesis is likely multifactorial, and the environment is a key component in our understanding of EoE.

Allergic Comorbidity in Eosinophilic Esophagitis: Mechanistic Relevance and Clinical Implications

Allergic eosinophilic esophagitis (EoE) is a chronic, allergen-mediated inflammatory disease of the esophagus, and the most common cause of prolonged dysphagia in children and young adults in the developed world. While initially undistinguished from gastroesophageal reflux disease-associated esophageal eosinophilia, EoE is now recognized as a clinically distinct entity that shares fundamental inflammatory features of other allergic conditions and is similarly increasing in incidence and prevalence. The clinical and epidemiologic associations between EoE and other allergic manifestations are well established. In addition to exaggerated rates of atopic dermatitis, IgE-mediated food allergy, asthma, and allergic rhinitis in EoE patients, each of these allergic manifestations imparts individual and cumulative risk for subsequent EoE diagnosis. As such, EoE may be a member of the "allergic march"-the natural history of allergic manifestations during childhood. Several determinants likely contribute to the relationship between these conditions, including shared genetic, environmental, and immunologic factors. Herein, we present a comprehensive review of allergic comorbidity in EoE. We discuss areas of the genome associated with both EoE and other allergic diseases, including the well-studied variants encoding thymic stromal lymphopoietin and calpain 14, among other "atopic" regions. We summarize ways that environmental factors (such as microbiome-altering pressures and aeroallergen exposure) may predispose to multiple allergic conditions including EoE. Finally, we touch on some fundamental features of type 2 inflammation, and the resulting implications for the development of multiple allergic manifestations. We conclude with an analysis of the "type 2" biologics, and how mechanistic similarities between EoE and the other allergic manifestations have important implications for screening and treatment of the allergic patient.

Molecular basis and cellular mechanisms of eosinophilic esophagitis for the clinical practice

Eosinophilic esophagitis (EoE) is a chronic, allergen-driven inflammatory esophageal disease characterized by predominantly eosinophilic inflammation leading to esophageal dysfunction. Recent efforts to understand EoE have increased our knowledge of the disease. Areas covered: Multiple cells, molecules, and genes interplay with early life environmental factors in the pathophysiology of EoE to converge in the esophageal epithelium at the center of disease pathogenesis. Epithelial cells constitute a mayor cytokine source for TSLP and Calpain-14; an impaired epithelial barrier function allowing penetration of food and microbiota-derived antigens is involved in triggering and maintaining inflammation. Eosinophil and mast cell-derived products, including TGFβ, together with IL-1β and TNFα, promote epithelial mesenchymal transition in EoE, contributing to tissue remodeling by synthetizing and depositing extracellular matrix in subepithelial layers. This article aims to provide a state-of-the-art update on the pathophysiology of EoE applied to clinical practice, and latest research and developments with potential interest to improve the diagnosis and treatment of patients with EoE are revised. Expert commentary: Preliminary approaches have provided promising results toward incorporating minimally invasive methods for patient diagnosis and monitoring in clinical practice. Early diagnosis and optimized therapies will allow for personalized medicine in EoE.

Incidence and prevalence of eosinophilic oesophagitis increase continiously in adults and children in Central Spain: A 12-year population-based study

OBJECTIVES

To update population-based incidence, prevalence and trends for eosinophilic oesophagitis (EoE) in children and adults over the past decade.

METHODS

All patients referred to our EoE unit and living in the study area up to December 2017 were prospectively registered. Endoscopy and pathology databases and clinical charts were manually reviewed. Diagnosis of EoE was confirmed upon symptoms of oesophageal dysfunction and eosinophilia >15 eos/HPF. Annual incidence rates and prevalence were estimated with confidence intervals (CI) of 95%.

RESULTS

A total of 117 patients, including 19 children, were diagnosed with EoE in the 2006-2017 period. In 2017, the prevalence of EoE in children was 111.9 (95%CI, 67.4-174.6) cases/100,000 inhabitants and in adults 111.9 (95%CI, 90.8-136.5) also, and in both cases was significantly higher for male patients. The highest prevalences were observed in ages ranging between 20 and 24 and 35-39 years old. Mean incidence rates of the study period were 10.6 and 9.1 new cases/100,000 inhabitants/year in children and adults, respectively. Rise in the appearance of EoE during the study period exceeded that for endoscopic procedures. No seasonal variation was observed in the diagnosis of EoE.

CONCLUSION

The incidence and prevalence of EoE has increased sharply in central Spain, beyond previous estimations, with one out of every 893 inhabitants now being diagnosed.

Pathophysiology of eosinophilic esophagitis: recent advances and their clinical implications

Introduction: Diagnostic and therapeutic strategies in eosinophilic esophagitis (EoE) are evolving. New knowledge regarding the pathophysiology of EoE has been the foundation for updated diagnostic recommendations and new therapeutic trials. Areas covered: We performed structured literature searches in Medline and PubMed, Cochrane meta-analyses, and abstracts of international congresses to review therapeutic approaches for EoE in July 2018. Additional articles were obtained by perusing the references of articles identified in the original PubMed search. Articles were excluded if they did not focus on the mechanism of disease, diagnosis, or treatment of humans with EoE. Expert commentary: Recent advances in the understanding of mechanisms underlying the pathology of EoE have resulted in significant change in the diagnostic algorithm for EoE, and are identifying promising potential targets for personalized medicine. There is a clinical need for improved targeted therapy for EoE, and better understanding the underlying pathophysiology of EoE will help to determine therapeutic targets. In this review, we highlight key mechanisms in the pathophysiology of EoE and how they are being utilized to change therapy in EoE.

Seasonal exacerbation of eosinophilic esophagitis histologic activity in adults and children implicates role of aeroallergens

BACKGROUND

Disease activity may correlate with environmental aeroallergen exposure in eosinophilic esophagitis. The association between seasons and flares of eosinophilic esophagitis (EoE) histologic activity has not been extensively studied.

OBJECTIVE

We aimed to assess the frequency of seasonal exacerbations of eosinophilic esophagitis, as well as changes in symptom reporting, endoscopic findings, and histologic findings attributed to aeroallergens in an EoE cohort.

METHODS

In this retrospective cohort study, we analyzed EoE patients in histologic remission (<15 eosinophil/high-power field) but who doubled the esophageal eosinophil count between seasons without change in eosinophilic esophagitis-specific therapy. Outcomes were: symptomatic global worsening (yes/no); change in endoscopic severity (EREFS scoring system); and histologic change (peak eosinophil count).

RESULTS

Of 782 patients, 13 (4%) met inclusion criteria (mean age: 36.2; 85% male; 86% white; 85% atopic disease diagnosis), and 14 exacerbations were recorded. Of these, 71% occurred in fall and summer months. Peak eosinophil counts increased from 6.8 to 86.8 eosinophil per high-power field (P < .001). Four patients (31%) reported worsening of seasonal allergies and 5 (38%) a global worsening of symptoms. Endoscopic severity was also significantly worse during seasonal exacerbations (total EREFS 3.7 vs 1.7; P = .01). Baseline features differed by atopic diagnoses and endoscopic findings between patients with and without seasonal exacerbations.

CONCLUSION

Seasonal exacerbations of eosinophilic esophagitis were uncommon in this cohort and most commonly recorded over the summer and fall months. These data support a role of aeroallergens in the pathogenesis of eosinophilic esophagitis in some patients, and clinicians should consider aeroallergens as a potential cause of disease exacerbation.

Does Aeroallergen Sensitization Cause or Contribute to Eosinophilic Esophagitis?

Eosinophilic esophagitis is an atopic disease defined clinically by esophageal symptoms in combination with a dense esophageal eosinophilia. EoE is triggered and maintained by exposure to certain foods and it is known that dietary modification controls symptoms and achieves disease remission. Recently, aeroallergens have been implicated in the pathogenesis of EoE. To examine the role of aeroallergens in EoE, we reviewed the published literature. Sensitization and production of IgE antibodies to foods and aeroallergens in subjects with EoE has been demonstrated. However, the evidence suggests only a minor role for IgE-mediated immune reactions in EoE. There is some evidence to support an association of EoE diagnosis and flares with environmental allergen exposure, and animal studies support the notion that EoE may be induced by exposure to inhalant allergens. Some studies show that newly diagnosed cases of EoE follow a seasonal pollen distribution (summer and spring), but the weight of evidence does not support the seasonal occurrence of diagnosis or worsening of symptoms. Overall, we conclude that the current evidence does not support causality in inhalant allergen exposure and the genesis nor exacerbations of EoE in humans, although there is a possibility that inhalant allergen sensitization could play a modifying role in EoE in the context of cross-reacting food allergens.

Eosinophilic Esophagitis: Review and Update

Background: Eosinophilic esophagitis (EoE) was first described in the 1990s, showing an increasing incidence and prevalence since then, being the leading cause of food impaction and the major cause of dysphagia. Probably, in a few years, EoE may no longer be considered a rare disease. Methods: This article discusses new aspects of the pathogenesis, symptoms, diagnosis, and treatment of EoE according to the last published guidelines. Results: The epidemiological studies indicate a multifactorial origin for EoE, where environmental and genetic factors take part. EoE affects both children and adults and it is frequently associated with atopic disease and IgE-mediated food allergies. In patients undergoing oral immunotherapy for desensitization from IgE-mediated food allergy the risk of developing EoE is 2.72%. Barrier dysfunction and T-helper 2 inflammation is considered to be pathogenetically important factors. There are different patterns of clinical presentation varying with age and can be masked by adaptation habits. Besides, symptoms do not usually correlate with histologic disease activity. The diagnostic criteria for EoE has evolved but mainly requires symptoms of esophageal dysfunction with histologic evidence of a peak value of at least 15 eosinophils per high-power field. Endoscopies have to be repeated in order to diagnose, monitor, and treat EoE. Treatment of EoE can be started either by drugs (PPIs and topical corticosteroids) or elimination diets. The multistage step-up elimination diet management approach of EoE is promising. Endoscopic dilation is used for patients with severe dysphagia/food impaction with inadequate response to anti-inflammatory treatment. Conclusions: Research in recent years has contributed to a better understanding of EoE's pathogenesis, genetic background, natural history, allergy workup, standardization in assessment of disease activity, evaluation of minimally invasive diagnostic tools, and new therapeutic approaches. However, several unmet needs are to be solved urgently, as finding a non-invasive disease-monitoring methods and biomarkers for routine practice, the development or new therapies, novel food allergy testing to detect triggering foods, drug, and doses required for initial therapy and safety issues with long-term maintenance therapy, amongst others. Besides, multidisciplinary management units of EoE, involving gastroenterologists, pediatricians, allergists, pathologists, dietitians, and ENT specialists are needed.

Assessing the incidence trend and characteristics of eosinophilic esophagitis in children in Olmsted County, Minnesota

Previous studies reported increased eosinophilic esophagitis (EoE) incidence in children. It is unclear whether this reported increased EoE incidence is true or due to increased recognition and diagnostic endoscopy among children. A population-based study that evaluated EoE incidence in OC, Minnesota, from 1976 to 2005 concluded that EoE incidence increased significantly over the past three 5-year intervals (from 0.35 [range: 0-0.87] per 100,000 person-years for 1991-1995 to 9.45 [range: 7.13-11.77] per 100,000 person-years for 2001-2005). The aim of this study is to assess the change of incidence and characteristics of EoE in children in the same population between 2005 and 2015 and compare the findings to those reported in the previous study. We retrospectively reviewed the electronic medical records from Olmsted Medical Center and Mayo Clinic between 2005 and 2015, using Rochester Epidemiology Project (REP) resources. All children with EoE diagnosis based on the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) guidelines were included. The incidence and characteristics of children with EoE during the study period were compared to those diagnosed between 1995 and 2005. The incidence of EoE in children adjusted for age and sex was 5.31 per 100,000 population person-years in 1995, 15.2 in 2005, and 19.2 in 2015. Change in annual incidence and seasonal variation were not significant, (P = .48) and (P = .32), respectively. Between 2005 and 2015, 73 children received an EoE diagnosis (boys 49; 67%) compared to 16 children (boys 10; 62.5) between 1995 and 2005. Mean (SD) age at diagnosis was 7.5 (5.2) and 12.8 (4.3) years, respectively. Symptoms differed by age of presentation, with vomiting the most common in children younger than 5 years (41.1% and 43.5%) and dysphagia in those older than 5 years (35.6% and 60.9%). The incidence of EoE was not increased for any specific age-group during the study period (P = .49). This study showed increased incidence of EoE in children in Olmsted County between 2005 and 2015 compared to the incidence between 1995 and 2005 (5.31 per 100,000 population person-years in 1995, 15.2 in 2005, and 19.2 in 2015). However, between 2005 and 2015, the change of incidence was not statically significant, (P = .48) despite the steady increase of EGD performed during the same time frame (64 in 2005 to 144 in 2015). By comparing children diagnosed between 2005 and 2015 to those diagnosed between 1995 and 2005, the mean age at diagnosis was younger in the former group, 7.5 versus 12.8 years. Vomiting replaced dysphagia as the most common clinical presentation. Otherwise, the presenting symptom of EoE in children remained consistent across specific age groups.

What Is the Relationship Between Eosinophilic Esophagitis (EoE) and Aeroallergens? Implications for Allergen Immunotherapy

PURPOSE OF REVIEW

Observations suggesting that aeroallergens trigger eosinophilic esophagitis (EoE) in a subset of patients raise questions about the implications this finding has on the evaluation and management of patients with EoE, including a potential role for allergen immunotherapy.

RECENT FINDINGS

The majority of studies evaluating the potential role of aeroallergens as provocateurs of EoE have addressed this issue by assessing the seasonal variation in EoE diagnosis and/or symptom onset or worsening, with mixed results. For various reasons, reaching accurate conclusions based on this methodology is potentially fraught with error. In addition, studies examining the even harder to assess role of perennial aeroallergens in triggering EoE are lacking. Although clearly not the majority, there may be a subset of patients with EoE and allergic rhinitis in whom exposure to aeroallergens to which they are sensitized contributes to esophageal eosinophilia either through direct chronic esophageal mucosal contact with pollen allergens or from repetitive exposure of the esophageal mucosa to pollen allergens, mediators, and eosinophils in swallowed nasal secretions. Therefore, evaluation for and optimal treatment of comorbid allergic rhinitis in EoE patients are clearly indicated. Recognition of the potential role of aeroallergens as triggers of EoE also raises the question of whether allergen immunotherapy might be an effective form of EoE treatment. Reports of sublingual immunotherapy (SLIT) inducing EoE support the notion that aeroallergens can trigger EoE, but negate this approach as a potential form of EoE therapy. In fact, the use of SLIT is contraindicated in patients with EoE. The literature regarding the role of subcutaneous immunotherapy (SCIT) in patients with EoE is limited. Current evidence indicates that it should not be typically recommended; however, SCIT might benefit a subset of patients with EoE and uncontrolled allergic rhinitis on conventional therapies in whom SCIT would otherwise be indicated for allergic rhinoconjunctivitis, particularly in those with sensitizations to pollens containing allergens that cross react with food allergens. The purpose of this review is to discuss the current literature examining the role of aeroallergens in triggering EoE with a focus on the potential clinical implications of this finding on managing patients with EoE.

Rising incidence and prevalence of adult eosinophilic esophagitis in midwestern Spain (2007-2016)

OBJECTIVES

Epidemiologic studies on eosinophilic esophagitis (EoE) are scarce and patient responders to proton pump inhibitor (PPI) therapy have usually been excluded. We aimed to evaluate population-based incidence rates, prevalence and trends in adult EoE over the past decade, including responders to PPI therapy.

METHODS

We conducted an analysis of a prospectively established case registry in the health area of Cáceres, located in midwestern Spain. From the first EoE case diagnosed in 2007, endoscopy and pathology reports up to December 2016 were manually reviewed. A baseline diagnosis of EoE was confirmed upon symptoms of esophageal dysfunction (dysphagia/food impaction) and esophageal eosinophilia ≥ 15 eos/HPF. All patients were re-evaluated on PPI therapy during follow-up.

RESULTS

A total of 137 patients were diagnosed with EoE during the study period, of whom 63 (46%) achieved clinicohistologic remission on PPI therapy. The prevalence of autoimmune disorders was low. Mean incidence rate was 8.09 new cases/100,000 inhabitants/year, increasing to 9.95 during the last lustrum and peaking in 2016 with 13.7. This trend coincided with late declining of esophageal biopsies rate. Overall prevalence in 2016 was 81.73 patients/100,000 inhabitants, with the highest prevalence in males between age 35 and 44 years (273 cases/100,000). No seasonal variation was observed in the diagnosis of EoE (53% during pollen season vs. 47%, p = 0.4).

CONCLUSIONS

In midwestern Spain, incidence (13.7 cases/100,000 inhabitants/year) and prevalence (81.73 patients/100,000 inhabitants) in 2016 have grown remarkably in just one decade, coming closer to those figures recently reported for Crohn's disease in Spain.

Pollen-food allergy syndrome is a common allergic comorbidity in adults with eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is associated with atopic diseases including asthma, allergic rhinitis, and atopic dermatitis; however, limited data exist on the correlation between pollen-food allergy syndrome (PFAS) and EoE. We analyzed 346 adults with EoE treated at a single center between 2002 and 2016. Demographic and EoE-specific data including clinical features and measures of EoE disease severity and treatments were collected. The presence of other atopic diseases, family history, prevalence of peripheral eosinophilia and elevated IgE, and details of PFAS triggers were collected. Twenty six percent of the 346 subjects in our cohort had both EoE and PFAS (EoE-PFAS). Compared to subjects with EoE alone, subjects with EoE-PFAS had an increased frequency of allergic rhinitis (86.7% vs. 64.2%, P < 0.001) and family history of allergies (71.1% vs. 53.3%, P = 0.003), and comprised a higher proportion of EoE diagnoses made in the spring (Χ2 < 0.001). 43.3% of subjects with concurrent EoE and PFAS opted for treatment with elimination diet, and these measures failed to induce remission in 46.2% of cases. In most cases, elimination diet failed despite strict avoidance of PFAS trigger foods in addition to common EoE triggers including dairy, wheat, and eggs. EoE-PFAS was also associated with higher serum IgE at the time of EoE diagnosis (460.6 vs. 289.9, P < 0.019). Allergic rhinitis and a family history of food allergy were independently associated with having EoE-PFAS. The most common triggers of PFAS in adults with EoE are apples (21.1%), carrots (15.5%), and peaches (15.5%). Along with asthma, allergic rhinitis and atopic dermatitis, PFAS is a common allergic comorbidity that is highly associated with EoE. Further studies aimed at understanding mechanistic similarities and differences of PFAS and EoE may shed light on the pathogenesis of these closely related food allergy syndromes.

Eosinophilic Esophagitis Clinical Manifestations and Differential Diagnosis

As a chronic inflammatory disease with eosinophilic infiltrate of the esophagus, eosinophilic esophagitis (EoE) causes a variety of gastrointestinal (GI) clinical manifestations. None of the symptoms, endoscopic features, or biopsy findings is pathognomonic of the disease, even with high degrees of esophageal eosinophilia. The pathogenesis has been explored by several studies, yet it still far from being completely understood. Evidence supports a role of allergen-driven Th2 lymphocyte mechanism, though not in every patient. This article addresses the disease's clinical manifestations, endoscopic findings, diagnosis, and differential diagnoses. In addition to the current diagnostic criteria, we summarize some recently emerging procedures that promise of enhancing more precise diagnosis and institution of early appropriate management, with consequent better quality of life and reduction of complications.

Incidence of eosinophilic esophagitis in the Netherlands continues to rise: 20-year results from a nationwide pathology database

BACKGROUND

The incidence of eosinophilic esophagitis (EoE) has increased rapidly. Most epidemiologic data were gathered in single-center studies over a short timeframe, possibly explaining the heterogeneous incidences.

AIM

The aim of this study was to retrospectively estimate the Dutch nationwide incidence of EoE over the last 20 years.

METHODS

The Dutch pathology registry (PALGA) was queried to identify pathology reports describing esophageal eosinophilia from 1996 to 2016. Cases were eligible if EoE was confirmed by the pathologist. Using the annual Dutch population data, the incidence of EoE was calculated.

KEY RESULTS

The search yielded 11 288 reports of which 5080 described esophageal eosinophilia. Eosinophilic esophagitis was diagnosed in 2161 patients, 1574 (73%) males and 365 (17%) children. The incidence increased from 0.01 (95% CI 0-0.02) in 1996 to 2.07 (95% CI 2.05-2.23) per 100 000 inhabitants in 2015. The incidence was higher in males than in females, 3.02 (95% CI 2.66-3.41) vs 1.14 (95% CI 0.93-1.38), odds ratio (OR) 2.66 (95% CI 2.10-3.36) and higher in adults than in children, 2.23 (95% CI 1.99-2.49) vs 1.46 (95% CI 1.09-1.91), OR 1.78 (95% CI 1.32-2.40). Incidence of EoE increased more than 200-fold, whereas endoscopy rates only tripled, from 30 in 1996 to 105 per 100 000 inhabitants in 2015. We observed no seasonal variation.

CONCLUSIONS AND INFERENCES

In the last decades, the Dutch EoE incidence has increased tremendously and still continues to rise. This expansion is only partially driven by increased endoscopy rates.

Demographic Features of Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is an increasingly prevalent chronic condition characterized by eosinophilic infiltration of the esophageal epithelium accompanied by esophageal symptoms. The number of new diagnoses is growing worldwide in both pediatric and adult populations. Differences in disease distribution and presentation have been found, varying by gender, race, and other characteristics. This review examines the existing literature and provides insight into the demographic features of EoE.

Association between atopic manifestations and eosinophilic esophagitis: A systematic review and meta-analysis

BACKGROUND

Eosinophilic esophagitis (EoE) has repeatedly been associated with atopic manifestations, which are reported more frequently in these patients than in the general population.

OBJECTIVE

To systematically assess the evidence and strength of the associations between EoE and atopy.

METHODS

We performed a systematic search of the MEDLINE, EMBASE, and SCOPUS databases for case-control studies comparing the frequency of atopic diatheses among patients with EoE and control subjects representing the general population without EoE. Using random-effects meta-analyses, we calculated summary estimates, including 95% confidence intervals (CIs), for bronchial asthma, atopic rhinitis, and eczema. Publication bias risks were assessed by means of funnel plot analysis and specific statistical tests.

RESULTS

Of the 2,954 references identified, data were collected from 21 studies, including a total of 53,542 patients with EoE and 54,759 controls. The criteria for defining a diagnosis of atopy in patients with EoE or controls was not structurally considered in most of the studies. Overall, allergic rhinitis was significantly more common among patients with EoE compared with control subjects (odds ratio [OR], 5.09; 95% CI, 2.91-8.90; I² = 86.7%) as were bronchial asthma (OR, 3.01; 95% CI, 1.96-4.62; I² = 84.5%) and eczema (OR, 2.85; 95% CI, 1.87-4.34; I² = 57.1%). Food allergies and other atopic conditions were also assessed. No significant publication bias was found for studies dealing with allergic rhinitis and eczema in EoE.

CONCLUSION

Despite pointing to a significant association between atopy and EoE, most of the studies provided no normalized diagnostic criteria for atopy. Further research should provide clear and standardized definitions of such conditions.

TRIAL REGISTRATION

www.crd.york.ac.uk/PROSPERO Trial Identifier: CRD42016036161.