Pathogenesis of esophageal rings in eosinophilic esophagitis

Dysmotility in Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is an immune mediated chronic inflammatory disease resulting from antigen exposure and is characterized by mucosal inflammation with eosinophils. Diagnosis is based on the histological finding of at least 15 eosinophils per high power field in esophageal biopsy specimens from upper gastrointestinal endoscopies. These endoscopies are usually performed in the setting of esophageal dysfunction, however, EoE can occasionally be incidentally diagnosed during endoscopies performed for other indications like coeliac disease. The eosinophilia is in the absence of other causes of esophageal eosinophilia (e.g., parasitic infection, esophageal leiomyomatosis or Crohn's disease). Presentation can be wide ranging and often varies according to age. Infants and younger children can present with choking/gagging, feed refusal, failure to thrive, irritability and vomiting. Older children and adults commonly present with dysphagia, chest pain or food bolus obstruction. EoE was first described in the 1970s, but was only recognized as a distinct disease entity in the 1990s. It has been rising in incidence and prevalence, with reported prevalence ranging between 1 in 2,500 and 1 in 10,000. Although the diagnosis of EoE is dependent on clear histopathologic diagnostic criteria, there is a disconnect between the degree of esophageal eosinophilia and symptom severity especially that of reported dysphagia. Multiple anatomical changes can be seen in the spectrum of presentations of EoE which explain dysphagia, including isolated strictures, diffuse trachealisation, fixed rings, including Schatzki, as well as tissue remodeling and fibrotic changes. However, a majority of EoE patients do not have any of these findings and will still often report ongoing dysphagia. Some will report ongoing dysphagia despite histological remission. This suggests an underlying esophageal dysmotilty which cannot be assessed with endoscopy or correlated with histological changes seen in biopsies. This review will describe the types of motor disturbances seen and their prevalence, the pathophysiological basis of dysmotility seen in EoE, how best to investigate esophageal dysfunction in EoE and the role of manometry in the management of EoE.

Pathophysiology of Dysphagia in Eosinophilic Esophagitis: Causes, Consequences, and Management

Eosinophilic esophagitis (EoE) is a leading cause of food bolus impaction in children and adults. The mechanism of dysphagia in EoE, particularly non-obstructive dysphagia, remains incompletely understood. While fibrostenotic processes appear to be critical in the development of dysphagia, somatosensory dysfunction and dysmotility also contribute. This review considers potential mechanisms of dysphagia and evaluates the utility of current and future treatment strategies in this context.

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.

Dietary treatment modulates mast cell phenotype, density, and activity in adult eosinophilic oesophagitis

BACKGROUND

Mast cells (MCs) are abundant in the inflammatory infiltrate in eosinophilic oesophagitis (EoE), but decrease with disease remission. However, their phenotype, role in the pathophysiology of the disease, and modulation after effective dietary therapy are still unclear.

OBJECTIVE

To define the phenotype of oesophageal MCs, their modulation through dietary therapy, and their association with clinical manifestations of EoE.

METHODS

Oesophageal mucosal samples from 10 adult patients with EoE obtained before and after effective six-food elimination diet (SFED) therapy, as well as from 10 control subjects were analysed. Eosinophil and MC density were quantified. Gene expression of chemoattractants for eosinophils (CCL11, CCL24, and CCL26), MCs (SCF), and their receptors (CCR3 and SCFR, respectively) were assessed by means of qPCR. Gene and protein expression of specific MC proteases (CPA3, CMA, and TPSB2) were evaluated with qPCR and immunofluorescence. Clinical manifestations and atopic background were recorded.

RESULTS

MC density was significantly increased in EoE compared with controls, decreasing after dietary treatment (18.6 to 1.44 cells/hpf, respectively; P < 0.001). The MCTC subtype predominated in the oesophageal mucosa (90%) in both patients with EoE and controls. Gene expression of MC-related proteases, eotaxins, and SCF were up-regulated in patients with EoE, but significantly decreased after therapy, regardless of atopic background. Epithelial peaks of MCs and eosinophils were significantly associated (ρ = 0.80) in EoE and correlated with the symptom score (ρ = 0.78). Gene expression of MC proteases and eotaxins also correlated with the symptom score (P < 0.05).

CONCLUSIONS AND CLINICAL RELEVANCE

MC and its proteases seem to play a relevant role in the pathophysiology and symptoms of EoE, which can be reversed after effective dietary treatment.

The pathophysiology of eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is an emerging disease characterized by esophageal eosinophilia (>15eos/hpf), lack of responsiveness to acid-suppressive medication and is managed by allergen elimination and anti-allergy therapy. Although the pathophysiology of EoE is currently unsubstantiated, evidence implicates food and aeroallergen hypersensitivity in genetically predisposed individuals as contributory factors. Genome-wide expression analyses have isolated a remarkably conserved gene-expression profile irrespective of age and gender, suggesting a genetic contribution. EoE has characteristics of mainly TH2 type immune responses but also some TH1 cytokines, which appear to strongly contribute to tissue fibrosis, with esophageal epithelial cells providing a hospitable environment for this inflammatory process. Eosinophil-degranulation products appear to play a central role in tissue remodeling in EoE. This remodeling and dysregulation predisposes to fibrosis. Mast-cell-derived molecules such as histamine may have an effect on enteric nerves and may also act in concert with transforming growth factor-β to interfere with esophageal musculature. Additionally, the esophageal epithelium may facilitate the inflammatory process under pathogenic contexts such as in EoE. This article aims to discuss the contributory factors in the pathophysiology of EoE.

Low grade esophageal eosinophilia in adults: an unrecognized part of the spectrum of eosinophilic esophagitis?

BACKGROUND

Eosinophilic esophagitis (EoE) is defined by a minimum of 15 eosinophils (eos) per high-powered field (HPF) on esophageal biopsy, along with esophageal symptoms and the exclusion of gastroesophageal reflux (GERD). The clinical significance of fewer eosinophils is unknown.

METHODS

Fifty-nine adult patients without a previous diagnosis of EoE with esophageal biopsies containing 1-14 eos per HPF (low grade eosinophilia) and 418 adult patients with ≥15 eos per HPF were identified by retrospective review. Patients were divided into group A (1-9 eos per HPF), group B (10-14 eos per HPF), and group C (≥15 eos per HPF) with a chart review of clinical and demographic data.

RESULTS

While dysphagia and atopy (asthma and allergic rhinitis) were more common in patients with ≥15 eos per HPF (group C) than those with low grade esophageal eosinophilia (groups A and B) (93 vs. 88%, P = 0.02), food impaction and heartburn occurred at an equal frequency across all patient groups. Endoscopic findings were likewise similar between groups. Of the 14 patients with low grade esophageal eosinophilia who underwent repeat endoscopy a mean interval of 42 weeks (range 8-118 weeks) later, five (36%) met conventional diagnostic criteria for EoE of 15 or greater eos per HPF. Follow-up in ten patients treated with topical corticosteroids noted improvement in nine, with mean follow-up of 8 weeks (range 4-12 weeks).

CONCLUSION

Some adult patients with dysphagia and less than 15 eos per HPF have similar endoscopic findings and clinical course to patients meeting the consensus definition of EoE. Further evaluation of patients with low grade esophageal eosinophilia is needed.

Role of mucosal inflammation in eosinophilic esophagitis: review of the literature

Eosinophilic esophagitis (EE) is increasingly recognized in adults. It is an inflammatory disease of the esophageal mucosa, with variable presentation, unresponsive to acid suppression therapy. The diagnosis requires histological confirmation of intense eosinophilic infiltration on esophageal biopsy specimen, however exact criteria required to make a diagnosis of EE is still being debated and a clear differentiation from gastroesophageal reflux disease (GERD) is important. Allergen elimination or anti-inflammatory therapy may be effective in such patients. The imperfect diagnostic criteria for EE mandate an understanding of the immunology and the pathophysiology of the disease. It may facilitate the introduction of novel treatment modalities in an individual unresponsive to acid suppression therapy. This paper describes basic elements of the immune-mediated injury to the esophageal mucosa and management aspects to provide a better understanding of the condition.

Do eosinophil numbers differentiate eosinophilic esophagitis from gastroesophageal reflux disease?

CONTEXT

Although the healthy esophageal mucosa contains no eosinophils, eosinophilic infiltration is observed in 2 major clinicopathologic settings: gastroesophageal reflux disease (GERD) and eosinophilic esophagitis (EE). The prevalence of EE is increasing in many countries, and this increase seems only partly to be due to a better awareness of the pathology, following the relatively recent description of EE. Gastroesophageal reflux disease and EE represent 2 entities that do not respond to the same treatment modalities and, thus, need to be distinguished. However, diagnostic criteria of EE have been defined arbitrarily, and the more recent articles tend to prove that the overlap with GERD is probably greater than initially believed, leading the authors to advise strict exclusion of GERD before considering the diagnosis of EE.

OBJECTIVES

To provide pathologists with the currently proposed histologic criteria of GERD and EE, to stress the need to combine these criteria with clinical data and endoscopic findings, and to outline the remaining controversies.

DATA SOURCES

This review is based on selected articles identified by a PubMed (US National Library of Medicine, Bethesda, Maryland) search of the literature in English for GERD and EE, a recent review by the American Gastroenterological Association (Bethesda), the Proceedings of the First International Gastrointestinal Eosinophil Research Symposium, and the authors' experience.

CONCLUSION

Proper identification of the etiology of eosinophilic infiltration of the esophagus allows accurate medical or surgical treatment and follow-up. Eosinophilic esophagitis and GERD diagnoses require integration of the histologic findings with the clinical and endoscopic data.

Esophageal dysmotility in children with eosinophilic esophagitis: a study using prolonged esophageal manometry

OBJECTIVES

The pathophysiology of dysphagia in patients with eosinophilic esophagitis (EoE) is unknown but may be related to abnormal esophageal motor function. Symptoms rarely occur during stationary esophageal manometry, so it has been difficult to establish an association between symptoms and motor events. Our aim was to evaluate esophageal motor function in children with EoE with the use of stationary manometry and ambulatory prolonged esophageal manometry and pH-metry (PEMP).

METHODS

PEMP was performed in children with EoE and compared with controls and children with gastroesophageal reflux disease (GERD). Peristalsis was considered effective when the esophageal contractions had a normal amplitude and propagation. Results are expressed as mean+/-s.e.

RESULTS

Seventeen patients with EoE, 13 with GERD, and 11 controls were studied. Values are expressed as mean+/-s.e. Stationary manometry identified abnormal peristalsis in 41% of children with EoE. During PEMP, children with EoE had an increased number of isolated (16.7+/-3.8 vs. 9.5+/-1.6 vs. 6.5+/-1.1; P<0.03) and high-amplitude contractions (4.1+/-1.2 vs. 1.8+/-0.8 vs. 0.1+/-0.1; P<0.03), and higher percentage ineffective peristalsis both during fasting (70.5%+/-2.5 vs. 57.8%+/-3.0 vs. 53.8%+/-1.9; P<0.05) and during meals (68.4+/-3.4 vs. 55.3+/-2.8 vs. 48.1+/-2.8; P<0.05) when compared with children with GERD and controls. Thirteen patients with EoE experienced 21 episodes of dysphagia, and all correlated with simultaneous abnormal motor function.

CONCLUSIONS

PEMP allowed the detection of ineffective peristalsis in children with EoE. Symptoms observed in children with EoE may be related to esophageal motor dysfunction.

Mechanism of eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a newly recognized disease and is an emerging entity throughout developing and developed countries, including the United States. Therefore, understanding the causes, natural history, diagnosis, and management is important for future therapeutic interventions. The pathogenesis of EoE is still not clear, but a growing body of evidence has established that this condition represents a T-cell-mediated immune response involving several proinflammatory mediators and chemoattractants known to regulate eosinophilic accumulation in the esophagus, such as IL-4, IL-5, IL-3 and eotaxin-1, -2, and -3. Determining the mechanism or mechanisms through which human esophageal-derived factors ultimately induce the functional abnormalities observed, and to which antigens patients who have EoE are sensitized that lead to the manifestation of symptoms, is of significant interest.

The role of mast cells in eosinophilic esophagitis

Eosinophilic esophagitis (EE) is a chronic inflammatory disease of the esophagus which is characterized by the presence of dense infiltrate of eosinophilic leukocytes restricted to this organ mucosa. Accumulating published evidence suggests a strong role of mast cells in the inflammatory infiltrate in the physiopathology of EE. We have reviewed published articles with relevant information about the presence and possible role of mast cells in EE. Although mast cells have been studied indirectly in EE, reported data allow us to confirm that the number of mast cells infiltrating the esophageal epithelium in adult and child patients with EE is higher with respect to the normal state and in gastroesophageal reflux disease. Mast cells linked to IgE, which are not found in other conditions, have been identified in EE. Despite that fact, an anaphylactic reaction history after exposure to allergens is not common in these patients. Therefore, the mast cells' function in EE could be dependent on T lymphocytes, as suggested by a mast cell gene expression analysis. Bi-directional crosstalk is established between mast cells and eosinophils, hence establishing interesting hypotheses regarding their relationship to EE physiopathology. Mast cells' function as an immune response leader seems to substitute for their effector functions in EE, while at the same time opening new research pathways for consideration of these cells as a therapeutic target in EE. However, the inefficiency of therapies that inhibit mast cell functions while they are effective in other respiratory tract diseases results in the need for specific studies to identify the real function of such complex cells in the physiopathology of EE. There is indirect proof of the role of mast cells in EE, while many doubts exist about their activation mechanism, which does not seem to be IgE-mediated. Specific approach studies are needed to clarify the function of these cells in the physiopathology of EE, which could be a possible therapeutic target.

Disturbances of esophageal motility in eosinophilic esophagitis: a case series

Esophageal manometry (EM) findings were reviewed in 14 (13 male) adults diagnosed with eosinophilic esophagitis (EE). One had complete nonperistaltic contractions (amplitude range = 30-180 mmHg) and incomplete relaxation of the lower esophageal sphincter (LES), suggesting vigorous achalasia. After 6 months of steroid therapy the repeat EM showed near-normal findings. One had total aperistalsis with contraction amplitudes less than 10 mmHg and a weak LES pressure (8 mmHg), criteria suggesting scleroderma. Two had low-amplitude (<30 mmHg) nonperistaltic contractions limited to the mid-esophagus. Criteria for nutcracker esophagus were met in two patients. Isolated low LES pressure (<15 mmHg) was observed in four patients who were also receiving proton pump inhibitors, and the remainder had normal EM findings. Our results found that EE can mimic all the categories of EM disturbances, with approximately 50% of our patients having a major impairment of smooth muscle function. The EM abnormality can be reversed to normal in some cases with appropriate treatment for EE.

Immunopathological mechanisms of eosinophilic oesophagitis

BACKGROUND

Eosinophilic oesophagitis (EO) is a chronic inflammatory disease of the oesophagus, with an emergent character, defined by the presence of a dense infiltrate by eosinophilic leukocytes restricted to the mucosa of this organ after excluding gastro-oesophageal acid reflux. It is manifested by chronic and/or recurrent dysphagia and episodes of oesophageal alimentary impaction, with great variation in terms of intensity, frequency, and duration of the attacks.

METHODS

An Internet-based search was performed for the most recent articles with relevant information concerning immunopathological mechanisms involved in EO.

RESULTS

Bibliographical data allow us to define that EO is related to an allergic or hypersensitivity-induced reaction after exposure to foods or inhalants, with increased prevalence of sensitisation to these allergens. Data published up to now suggest a cellular hypersensitivity reaction rather than a humoral one in the physiopathology of EO. In this disease, sensitised T-lymphocytes mediate a Th2 type response, releasing cytokines such as IL-5, with a possible Th1 component that requires further investigation. The function of the abundant CD8+ T-lymphocytes present in the oesophageal epithelium has yet to be explained. Mast cells also participate in epithelial inflammatory infiltrate in EO, and it is still unknown if its activation, mainly through IgE, contributes to the immunopathology of the disease even though EO rarely manifests immediate hypersensitivity reactions. IL-5 and different forms of eotaxins perform an important active role in the recruitment of eosinophils to the oesophagus.

CONCLUSIONS

EO is an immunologically complex and little studied entity that is associated with other allergic diseases and in which different effector cells participate, determining an immunological response of cellular rather than a humoral hypersensitivity reaction. The data available point out that EO is a disorder of the Th2 retarded immune response, in which the triggering factor might not be IgE. Although the final inflammatory phenomena observed in EO are common for the different patients, the cascade of inflammatory mediators that lead to them might not be identical in all cases, and the morphological and functional disorders observed in EO would represent the final convergence of different activation forms of the mechanisms of inflammation.

Esophageal dysphagia

Esophageal dysphagia can arise from a variety of causes such as motility disorders, mechanical and inflammatory diseases. Adequate management includes a detailed history, evaluation with upper endoscopy, barium radiography and manometry. Treatment is usually tailored to the underlying disease process and in some cases, as in inoperable cancer, palliative management may be necessary.

Eosinophilic oesophagitis: a common cause of dysphagia in young adults?

Eosinophilic oesophagitis (EO) is an increasingly recognised chronic, relapsing inflammatory condition of the oesophagus. There has been a mini-epidemic of EO in the last decade. The incidence of this condition is higher in children and is commoner in males. There is either a family or personal history of atopic conditions present in a significant number of patients and can also be familial in up to 10%. The classical symptom in an adult is chronic, intermittent solid-food dysphagia and food impaction, often necessitating emergency endoscopic removal. Despite the history of dysphagia for a number of years, patients remain well with no weight loss, which can mislead clinicians to diagnose a functional problem with a resulting delay in the diagnosis. There are various endoscopic features of EO; commonly multiple rings and linear furrows, though these can be subtle and the mucosa may be macroscopically normal. The hallmark of this condition is the histological presence of > or =15 eosinophils/high power field (HPF) in the oesophageal mucosa. Therapeutic options include avoidance of dietary allergens, topical or systemic steroids, Montelukast, Mepolizumab (anti-IL-5 antibody) and endoscopic dilation of strictures unresponsive to medical therapy.

Basic pathogenesis of eosinophilic esophagitis

Eosinophilic esophagitis (EE) is a newly recognized disease, which has largely been called idiopathic EE, emphasizing the poor understanding of its pathogenesis. EE is a severe disease of the esophagus characterized by an accumulation of eosinophils in the esophageal mucosa, and is highly associated with atopic disease. Nevertheless, the nomenclature "eosinophilic esophagitis" describes only the tip of the iceberg of a complex disorder, as the pathogenesis of EE involves multiple tissues, cell types, and genes, and derives from complex genetic and environmental factors. This article defines the fundamental knowledge available to date that characterizes the mechanisms by which certain etiological factors cause EE, reviewing human studies, murine models, and recent knowledge regarding the involvement of environmental, cellular, molecular, and genetic factors in the development of EE.

Esophageal dysmotility in patients who have eosinophilic esophagitis

The understanding of esophageal motility alterations in patients who have eosinophilic esophagitis (EE) is in its infancy despite the common presenting complaint of dysphagia. A diversity of motility disorders has been reported in patients who have EE including achalasia, diffuse esophageal spasm, nutcracker esophagus, and nonspecific motility alterations including high-amplitude esophageal body contractions, tertiary contractions, abnormalities in lower esophageal sphincter pressure, and other peristaltic problems. Some evidence suggests that treatment of EE will improve motility. Technological advances such as high-resolution manometry and combined manometry with impedance may provide new insight into more subtle motility abnormalities.

Eosinophilic esophagitis: is it all allergies?

Eosinophilic esophagitis (EE) is an increasingly recognized disorder in the adult population, most often manifested by symptoms of dysphagia and food impaction. Mechanisms involving eotaxin-3, interleukin 5, and signal transducer and activator of transcription 6 have been studied and may represent future therapeutic targets. Patients commonly have a personal and family history of atopy, and both food allergies and aeroallergens have also been investigated as triggers of EE. Traditional allergy-testing methods, including skin prick testing and specific IgE testing, have been used to identify food and environmental allergies. However, new studies suggest that patch testing could add to diagnostic accuracy in EE because the disorder might not be a classic type I allergic response. Although studies of treatment of adults with EE have thus far focused on swallowed fluticasone proprionate, many trials in children have assessed the efficacy of food elimination and elemental diets. These diets, which have been extremely successful in reducing symptoms, have also been shown to induce histological improvement and remission. No similar studies have been conducted in adults; the tolerability of such an intervention may prove more difficult in this population. This article reviews the underlying pathophysiology of EE and describes evolving options for more accurately identifying food and environmental allergies. We also discuss the pediatric trials using food elimination and avoidance diets and suggest that this type of intervention may be an important area of future research in the adult population.

Eosinophilic oesophagitis: epidemiology, clinical aspects, and association to allergy

Eosinophilic oesophagitis is characterised by age-dependent symptoms mimicking gastrooesophageal reflux disease, a distinct endoscopic appearance and a histological picture with extensive infiltration of eosinophils in the oesophageal mucosa. Eosinophilic oesophagitis is more frequently seen in males, and patients often belong to the paediatric or adolescence age groups. The exact prevalence of eosinophilic oesophagitis is unknown, but it has been suggested that the United States has a higher prevalence than Europe. Several treatment algorithms have been suggested, including elemental diets, oral steroids, inhaled (swallowed) steroids, and leucotriene receptor antagonists. Detailed information on the eosinophilic inflammatory processes in the oesophageal mucosa was initially obtained from animal models, in particular with regard to the role of interleukin-5 and the chemokine eotaxin-1 in eosinophilic recruitment. Studies have suggested a cytotoxic effect of eosinophilic degranulation products on nerve fibers in the gastric/intestinal mucosa, implicating a direct effect of allergic inflammation on gastrointestinal motility. Human studies recently have emphasized the role of eotaxin-3 and identified a single nucleotide polymorphism probably related to disease susceptibility.

Esofagitis eosinofílica. Revisión de los conceptos fisiopatológicos y clínicos actuales

Eosinophilc esophagitis (EE) is an emerging disease which is characterized by a dense infiltration of the esophagus by eosinophilic leukocytes. The main symptoms of this disease are dysphagia and frequent food impaction in esophagus, and they are due to a hypersentivity response to different foods or aeroallergens. Eosinophil accumulation in the esophageal epithelium is determined by local production of eosinophilotropic cytokines and chemokines, which have been well defined as a TH2-type hypersensitivity reaction in animal models of the disease. Esophageal epithelium, after T CD4+ lymphocytes stimulation, contains all the necessary cell types for the development of local immunoallergic responses. However, there is increasing data on the significant role that humoral immunity could play in the pathophysiology of EE, by means of the action of IgE over mast cells function. The high density of T CD8+ lymphocytes in inflammatory infiltrate suggests that a TH1-type reaction could also participate in the mechanism of the disease. Proteins contained in cytoplasmic granules of activated eosinophils and mast cells could act over neural and muscular components of the esophageal wall, triggering motor disturbances which can be measured by means of manometric recordings and justify the esophageal symptoms. This paper aims to review the newest clinical aspects of EE and the results of studies directed at investigating the pathophysiology of the disease. Furthermore, we carry out a critical review of available therapeutic options.

Upper gastrointestinal tract eosinophilic disorders: pathobiology and management

Patients with eosinophilic esophagitis present with symptoms similar to those from gastroesophageal reflux disease along with dense esophageal eosinophilia (normal gastric and duodenal biopsies) that persist despite aggressive acid blockade. The dramatic increase in prevalence of eosinophilic esophagitis over the past several years provides clinicians with a new explanation for previously unexplained dysphagia, food impaction, vomiting, and abdominal pain. As a product of this recognition, an increasing number of basic and translational studies are building a new understanding of the pathogenesis of esophageal eosinophilia. This review addresses recent studies that define clinical features, genetic predisposition, pathogenetic mechanisms, and treatment options for eosinophilic esophagitis.

Eosinophilic esophagitis: treatment in 2005

PURPOSE OF REVIEW

Eosinophilic esophagitis is an isolated, eosinophilic inflammation of the esophagus. The symptoms are often confused for those of gastroesophageal reflux. Over the past few years, there has been a significant increase in the literature surrounding eosinophilic esophagitis as more than two-thirds of the articles written on the subject have been published within the past 3 years. Because the incidence is rising and the condition is easily diagnosed by endoscopy with biopsy, it is important for physicians to understand the pathophysiology, clinical presentation, and treatment options available for patients.

RECENT FINDINGS

The etiology of eosinophilic esophagitis in children is reported to be associated with an allergic response to food antigens. Because allergy tests are often unable to determine the causative foods, complete elimination of all foods is often required. The diagnosis requires a biopsy of the esophagus, stomach and duodenum. The condition is diagnosed if the patient's esophageal biopsy depicts over 20 eosinophils per high-powered field despite the use of aggressive acid blockade, biopsies of the stomach antrum and duodenum are normal, and the tissue inflammation resolves when dietary antigens are removed from the diet. While the most commonly involved foods causing eosinophilic esophagitis include milk, eggs, nuts, beef, wheat, fish, shellfish, corn and soy, almost all foods have been implicated. Alternative treatments include esophageal dilatation and medical therapy.

SUMMARY

This article reviews the past year's literature, concentrating on the pathophysiology, and treatment of eosinophilic esophagitis in both children and adults.

Food allergy and constipation in childhood: how functional is it?

An increasing incidence of food allergy, especially to cow's milk proteins, is observed in children living in the industrialized regions of the world. In some cases responding to an eviction diet excluding offending foods, the 'functional' constipation can be caused by inflammation of the intestinal wall infiltrated by eosinophils. Understanding the complex mechanisms involved could help to improve the management of idiopathic functional constipation in children by addressing the aetiology instead of treating the symptoms.

Eosinophilic esophagitis in adults: a systematic review

BACKGROUND/AIMS

Eosinophilic esophagitis (EE) is an increasingly recognized condition both in children and adults. The aim of the present study was to review the available evidence regarding EE in adults.

METHODS

PubMed, MEDLINE and medical textbooks were searched in May-June 2005 for English-language articles published between January 1978 and June 2005 containing relevant terms. The abstracts of two major conferences from 2000 to June 2005 were also reviewed. The presence of more than 15 eosinophils per high power field on esophageal biopsies was required to establish the diagnosis.

RESULTS

Twenty-four studies with 325 patients (male/female ratio: 3/1) were found that met the review criteria. Presenting symptoms included dysphagia (93%), food impaction (62%) and heartburn (23.6%). An allergic history and peripheral eosinophilia was noted in 51.6 and 30.8% of patients, respectively. Esophageal manometry presented evidence of a motility disorder in 40% of cases. Endoscopic findings included mucosal fragility/oedema, rings, strictures, whitish pinpoint exudates and small-calibre esophagus in 59.3, 49.2, 39.7, 15.7 and 5.3% of cases, respectively, whereas 8.8% of patients had a normal endoscopy. Bougienage was performed in 64 patients, with limited efficacy and an increased complication rate. The administration of corticosteroids resulted in symptomatic improvement in more than 95% of cases.

CONCLUSIONS

An allergic history and peripheral eosinophilia is less common in adults than among children with EE. An esophageal motility disorder should be a novel indication for biopsies in adults with long-lasting dysphagia. A trial with corticosteroids before bougienage may reduce active inflammation and the complication rate.