Diagnosis, management and therapeutic options for eosinophilic esophagitis.

PURPOSE OF REVIEW: Eosinophilic esophagitis is a chronic and commonly evolving condition leading to relevant and potentially irreversible burden in terms of tissue damage and related functional impairment, thus significantly impacting on quality of life. The aim of the present review is to summarize the recent advances in terms of diagnostic work-up and pharmacological and nonpharmacological management of the disease, under the broader perspective of type 2 inflammation. RECENT FINDINGS: Two major novelties have prompted an innovative approach to EoE. In terms of diagnosis, it has been proposed to dissect the disease heterogeneity in three endotypes, independent from tissue eosinophil number: EoEe1, characterized by normal appearing oesophagus; EoEe2, associated with type 2 inflammation and steroid-refractoriness; EoEe3, whose features include adult onset, a more fibro-stenotic aspect and loss of epithelial gene expression. Concerning treatment, two recently licensed drugs for EoE, oro-dispersible budesonide and dupilumab represent the first treatment options specifically developed for EoE and addressing EoE-related peculiar pathobiological features. SUMMARY: In the era of precision medicine, managing EoE according to a phenotype-driven approach might be helpful in defining the best treatment options in the different disease forms or stages. In addition, exploring the coexistence or the previous occurrence of other type 2 conditions may suggest the opportunity to specifically target type 2 inflammation through biologic therapy. The complex EoE pathobiology combining inflammatory and functional features, both at organ and systemic level, requires a multidimensional approach relying on the strict integration of gastroenterologists and allergist-immunologists.

Eosinophilic Esophagitis: Clinical Pearls for Primary Care Providers and Gastroenterologists.

Eosinophilic esophagitis (EoE) is a chronic and progressive immune-mediated esophageal disorder. Given its increasing incidence, it is now a leading cause of dysphagia and food impaction in the United States. Eosinophilic esophagitis is most common in adult White men and has a high concurrence rate with other atopic conditions like allergic rhinitis, bronchial asthma, and eczema. The initial presentation includes symptoms of esophageal dysfunction, classically solid-food dysphagia. Without treatment, inflammation can progress to fibrosis with the formation of strictures, leading to complications such as food impaction. It is a clinicopathologic disease requiring compatible clinical symptoms and histologic evidence of eosinophil-predominant inflammation of the esophageal epithelium with more than 15 eosinophils per high-power field. The mainstay of management includes the 3 d's (diet, drugs, dilation): dietary modifications to eliminate trigger food groups; medications including proton pump inhibitors, swallowed topical glucocorticoids, and dupilumab; and esophageal dilation to manage strictures. Various elimination diets have been found to be effective, including 1-food, 2-food, 4-food, and 6-food elimination diets. Dupilumab, a humanized monoclonal antibody that regulates interleukin 4 and 13 signaling pathways, has shown promising results in clinical trials and was approved by the Food and Drug Administration in 2022 for use in EoE. Symptom alleviation, although important, is not the sole end point of treatment in EoE as persistent inflammation, even in the absence of symptoms, can lead to esophageal fibrosis and stricture formation over time. The chronic nature and high recurrence rates of EoE warrant maintenance therapy in patients with EoE after initial remission is achieved.

Pathophysiology and Clinical Impact of Esophageal Remodeling and Fibrosis in Eosinophilic Esophagitis.

Most of the major clinical signs and consequences of eosinophilic esophagitis seem to be related to tissue remodeling. Important data on remodeling activity in patients with eosinophilic esophagitis are provided by a range of current and new biologic markers and diagnostics. To completely clarify the possible advantages and restrictions of therapeutic approaches, clinical studies should take into consideration the existence and reversibility of esophageal remodeling. The degree of mucosal or submucosal disease activity may not be reflected by epithelial eosinophilic inflammation, which is used to define one criterion of disease activity".

Clinical Evaluation of the Child with Eosinophilic Esophagitis.

The diagnosis of eosinophilic esophagitis (EoE) is based on clinical symptoms of esophageal dysfunction and eosinophil predominant esophageal inflammation. Clinical symptoms in children with EoE vary based on age and may be nonspecific. EoE has a male predominance with the majority having comorbid atopic disorders. At present, treatment options include medications (proton pump inhibition, swallowed topical steroids), dietary therapy or biologic therapy (dupilumab, approved for those ≥12 years of age). Outside of EoE in the context of oral immunotherapy, EoE is typically chronic requiring lifelong therapy. Long-term complications including feeding difficulties, malnutrition, and fibrostenotic disease.

Clinical Evaluation of the Adult with Eosinophilic Esophagitis.

Adult patients with eosinophilic esophagitis (EoE) typically present with a history of dysphagia for solids, sometimes with additional reflux-like pain and a history of prior food impactions. In contrast to these alarming symptoms, the general appearance and physical examination of adult patients with EoE is in line with apparently healthy individuals. Therefore, the diagnosis is based on a history of solid-food dysphagia and eosinophilic tissue infiltration. Importantly, the increasing prevalence of EoE variants, that is, typical EoE symptoms in the absence of a relevant eosinophilia, and several studies with eosinophil-targeting drugs, call the pathogenic role of eosinophils into question.

Endoscopic Features of Eosinophilic Esophagitis.

Edema, rings, exudates, furrows, and strictures (EREFS) represent the major endoscopic features of eosinophilic esophagitis (EoE). The Endoscopic Reference System (EREFS) grading system is easy to learn and apply during daily clinical practice in the diagnosis and follow-up of EoE patients. When endoscopy is performed by an EoE-experienced physician, the EREFS criteria will identify the majority of EoE patients. The EREFS score from the area of greatest involvement of the esophagus should be reported. The EREFS grading system was formally validated as an endoscopy score and several randomized placebo-controlled trials have shown responsiveness of the EREFS score to therapeutic interventions.

Histopathology of Eosinophilic Esophagitis.

Microscopic examination of esophageal biopsies is essential to diagnose eosinophilic esophagitis (EoE). Eosinophil inflammation is the basis for the diagnosis, but additional abnormalities may contribute to persistent symptoms and epithelial barrier dysfunction. Both peak eosinophil count and assessments of additional features should be included in pre-therapy and post-therapy pathology reports. Pathologic abnormalities identified in esophageal biopsies of EoE are reversible in contrast to esophageal strictures.

Dietary Management of Eosinophilic Esophagitis.

Eosinophilic esophagitis (EoE) is a chronic immune-mediated food allergy-driven disease characterized by eosinophilic inflammation of the esophagus leading to symptoms of esophageal dysfunction. Prior studies have supported the key role of food allergen exposure as the main driver behind the etiopathogenesis showing that removal of food antigens can result in disease remission in both children and adults. These landmark studies serve as the basis for the rising interest and evolution of dietary therapy in EoE. This article will focus on the rationale for dietary therapy in EoE and provide helpful tools for the implementation of dietary therapy in practice.

Recognition and Management of Feeding Dysfunction in the Pediatric Patient with Eosinophilic Esophagitis.

Feeding is a complex skill requiring coordination of multiple body systems. Multiple factors are considered in feeding dysfunction in pediatric patients with eosinophilic gastrointestinal disorders, including overall development, nutritional status, mealtime behaviors, and medical comorbidities. Symptoms of feeding dysfunction vary by age, with maladaptive learned feeding behaviors spanning all age ranges. Knowledge of the normal acquisition of feeding skills is critical to interpret the impact of the disease and plan appropriate intervention. Assessment and treatment from a feeding and swallowing disorders specialist can dramatically impact successful outcomes in nutrition, growth, mealtime dynamics and ultimatly quality of life for children and their caregivers in home and social settings.

Pathophysiology of Non-Esophageal Eosinophilic Gastrointestinal Disorders.

Eosinophilic gastrointestinal disorder (EGID) is an umbrella term encompassing a group of chronic, immune-mediated disorders characterized by eosinophil-rich inflammation affecting one or more segments of the gastrointestinal tract. A recent consensus in nomenclature and emerging data made possible through multi-center consortia are beginning to unravel the molecular and cellular underpinnings of EGIDs below the esophagus. These emerging findings are revealing both overarching commonalities related to a food allergen-driven, chronic, Th2-mediated immune response as well as location-specific nuances in the pathophysiology of the collective EGIDs. Altogether, these advances offer promise for improved diagnoses and more efficacious interventional strategies.

Role of Mast Cells in Eosinophilic Gastrointestinal Diseases.

Mast cells play a central role in the pathogenesis of eosinophilic gastrointestinal disorders (EGIDs), including eosinophilic esophagitis. Their interactions with immune and structural cells, involvement in tissue remodeling, and contribution to symptoms make them attractive targets for therapeutic intervention. More is being discovered regarding the intricate interplay of mast cells and eosinophils. Recent studies demonstrating that depletion of eosinophils is insufficient to improve symptoms of EGIDs have raised the question of whether other cells may play a role in symptomatology and pathogenesis of EGIDs.

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).

Health-Related Quality of Life in Patients with Eosinophilic Esophagitis.

Measuring health-related quality of life (HRQOL) gained relevance in research and clinical practice in patients with eosinophilic esophagitis. The physical discomfort and social and psychological consequences of this food-related disease substantially affect HRQOL. Determinant of an impaired HRQOL include symptom severity, disease duration, biological disease activity, and psychological factors. Patients prioritize symptom relief and improved HRQOL as treatment objectives. Available treatment options can address these goals; however, there is a suboptimal adherence to treatment. There is a need for enhanced patient guidance and education. The assessment of HRQOL will help to prioritize patient's needs in management.

Embracing Diversity, Equity, Inclusion, and Accessibility in Eosinophilic Gastrointestinal Diseases.

Eosinophilic gastrointestinal diseases (EGIDs) including eosinophilic esophagitis (EoE) are rare diseases in which eosinophils abnormally infiltrate the gastrointestinal tract. Because these are rare diseases, there is limited information regarding race and ethnicity in EGIDs and even less is known about the impact of socioeconomic factors. There is some evidence that access to care in rural settings may be affecting epidemiologic understanding of EGIDs in the pediatric populations. Future work should try to evaluate bias in research and strive for representation in clinical trials and medicine.

Endoscopic Features of Eosinophilic Gastrointestinal Diseases.

Endoscopic evaluation with biopsies is a mainstay of the diagnosis of eosinophilic esophagitis (EoE) and non-EoE eosinophilic gastrointestinal diseases (EGIDs). Increasing knowledge has resulted in the development of 2 standardized scoring systems: the Endoscopic REFerence Score (EREFS) for EoE and the EG-REFS for eosinophilic gastritis, although the latter has not been validated. In EGIDs, diagnosis and follow-up focus on eosinophil infiltration in biopsies. In this article, we will discuss the most commonly used endoscopic scores in EoE and non-EoE EGIDs, their validity for the diagnosis and follow-up of disease activity, as well as endoscopic interventions and areas of uncertainty.

Histopathology of Eosinophilic Gastrointestinal Diseases Beyond Eosinophilic Esophagitis.

Eosinophilic gastrointestinal diseases (EGID), such as eosinophilic gastritis (EoG), eosinophilic enteritis, and eosinophilic colitis (EoC), are chronic inflammatory conditions characterized by persistent gastrointestinal symptoms and elevated levels of activated eosinophils in the gastrointestinal tract. EoG and eosinophilic duodenitis (EoD) are strongly associated with food allergen triggers and TH2 inflammation, whereas EoC shows minimal transcriptomic overlap with other EGIDs. The level of expression of certain genes associated with TH2 immune response is associated with certain histopathologic findings of EoG, EoD, and EoC. Current immune therapy for EoG depletes tissue eosinophilia with persistence of other histopathologic features of disease.

Clinical Presentation of Patients with Eosinophilic Gastrointestinal Diseases beyond Eosinophilic Esophagitis.

The clinical presentation of eosinophilic gastrointestinal diseases beyond eosinophilic esophagitis (non-EoE EGIDs) varies depending on the gastrointestinal segments affected by the eosinophilic inflammation, the extent of eosinophilic inflammation within the gastrointestinal tract and its depth through the bowel wall. Non-EoE EGIDs with mucosal involvement tend to present with diarrhea, malabsorption, and sometimes bleeding, those with muscular involvement may present with symptoms of obstruction or pseudo-obstruction, intussusception, and even perforation, whereas those with serosal involvement may present with eosinophilic ascites. Here we describe the differences in symptoms experienced by children with non-EoE EGIDs with varying degrees of eosinophilic inflammation through the bowel wall.

The Relationship Between Eosinophilic Esophagitis and Immunotherapy.

Immunotherapy is a treatment approach based on the principle of incremental allergen exposure to achieve desensitization. Recently, oral immunotherapy has been introduced as a treatment of IgE-mediated food allergy. Some patients receiving oral immunotherapy for food allergy may develop eosinophilic esophagitis. Here, we summarize the literature examining this association, its treatment, and outcomes and discuss possible explanations for this clinical phenomenon. We further identify potential associations with aeroallergen sensitivity and other forms of immunotherapy including subcutaneous immunotherapy and sublingual immunotherapy. Finally, we discuss management of immunotherapy-induced eosinophilic esophagitis. Epicutaneous immunotherapy is highlighted as an area of therapeutic investigation.