Low levels of adherence with proton pump inhibitor therapy contribute to therapeutic failure in gastroesophageal reflux disease

Magnetic sphincter augmentation: considerations for use in Barrett's esophagus

Barrett's esophagus (BE) occurs in 5-15% of patients with gastroesophageal reflux disease (GERD). While acid suppressive therapy is a critical component of BE management to minimize the risk of progression to esophageal adenocarcinoma, surgical control of mechanical reflux is sometimes necessary. Magnetic sphincter augmentation (MSA) is an increasingly utilized anti-reflux surgical therapy for GERD. While the use of MSA is listed as a precaution by the United States Food and Drug Administration, there are limited data showing effective BE regression with MSA. MSA offers several advantages in BE including effective reflux control, anti-reflux barrier restoration and reduced hiatal hernia recurrence. However, careful patient selection for MSA is necessary.

Laparoscopic total fundoplication is superior to medical treatment for reducing the cancer risk in Barrett's esophagus: a long-term analysis

The present study aims to compare the effectiveness of surgical and medical therapy in reducing the risk of cancer in Barrett's esophagus in a long-term evaluation. A prospective cohort was designed that compared Barrett's esophagus patients submitted to medical treatment with omeprazole or laparoscopic Nissen fundoplication. The groups were compared using propensity score matching paired by Barrett's esophagus length. A total of 398 patients met inclusion criteria. There were 207 patients in the omeprazole group (Group A) and 191 in the total fundoplication group (Group B). After applying the propensity score matching paired by Barrett's esophagus length, the groups were 180 (Group A) and 190 (Group B). Median follow-up was 80 months. Group B was significantly superior for controlling GERD symptoms. Group B was more efficient than Group A in promoting Barrett's esophagus regression or blocking its progression. Group B was more efficient than Group A in preventing the development of dysplasia and cancer. Logistic regression was performed for the outcomes of adenocarcinoma and dysplasia. Age and body mass index were used as covariates in the logistic regression models. Even after regression analysis, Group B was still superior to Group A to prevent esophageal adenocarcinoma or dysplasia transformation (odds ratio [OR]: 0.51; 95% confidence interval [CI]: 0.27-0.97, for adenocarcinoma or any dysplasia; and OR: 0.26; 95% CI: 0.08-0.81, for adenocarcinoma or high-grade dysplasia). Surgical treatment is superior to medical management, allowing for better symptom control, less need for reflux medication use, higher regression rate of the columnar epithelium and intestinal metaplasia, and lower risk for progression to dysplasia and cancer.

Knowledge gaps in the management of refractory reflux-like symptoms: Healthcare provider survey

BACKGROUND

Refractory reflux-like symptoms have a substantial impact on patients and healthcare providers. The aim of the survey was to qualitatively assess the needs and attitudes of practicing clinicians around the management of refractory reflux symptoms and refractory gastroesophageal reflux disease (rGERD).

METHODS

An International Working Group for the Classification of Oesophagitis (IWGCO) steering committee invited clinicians to complete an online survey including 17 questions.

KEY RESULTS

Of the 113 clinicians who completed the survey, 70% were GIs, 20% were primary care physicians, and 10% were other specialties. Functional heartburn was considered the most common reason for an incomplete response to proton pump inhibitor (PPI) therapy (82%), followed by stress/anxiety (69%). More GIs identified esophageal hypersensitivity as a cause, while more non-GIs identified esophageal dysmotility and non-reflux-related esophageal conditions. As the first step, most clinicians would order investigations (70-88%). Overall, 72% would add supplemental therapy for patients with partial response, but only 58% for those with non-response. Antacid/alginate was the most common choice overall, while non-GIs were more likely to add a prokinetic than were GIs (47.8 vs. 24.1%). Approximately 40% of clinicians would switch PPIs in patients with partial response, but only 29% would do so in non-responders. Preferences for long-term therapy were highly variable. The most common initial investigation was upper endoscopy. Choice of esophageal manometry and pH monitoring was more variable, with no clear preference for whether pH monitoring should be conducted on, or off, PPI therapy.

CONCLUSIONS AND INFERENCES

The survey identified a number of challenges for clinicians, especially non-GI physicians, treating patients with refractory reflux-like symptoms or rGERD on a daily basis.

Comparison in Adherence to Treatment between Patients with Mild-Moderate and Severe Reflux Esophagitis: A Prospective Study

Purpose: Gastro-esophageal reflux disease (GERD) is prevalent and causes erosive esophagitis (EE) with varying degrees of severity (A to D according to the Los Angeles Classification). Adherence to medical therapy is crucial for treatment success. We compared adherence to treatment recommendations between patients with EE grades C/D and A/B. Methods: A follow-up study was conducted during 2019−2020 among GERD patients who underwent a diagnostic gastroscopy 1−4 years earlier. Telephone interviews were conducted with patients diagnosed with severe EE grades C/D (n = 99) and randomly selected patients with mild−moderate EE grades A/B (n = 50). Patients with grades A/B were classified as adherent if they took proton pump inhibitors (PPIs) for 2−3 months as recommended. Patients with grades C/D were classified as adherent if they took medications for a prolonged period (>6 months) and performed a follow-up endoscopy as recommended. Results: The mean age of the participants was 44.6 years (SD = 15.1). The mean duration of PPIs therapy in patients with EE grades A/B was 9.4 months (SD = 8.7). Fourteen (14.2%) patients with EE grades A/B were non-adherent to treatment, compared to 21 (40.8%) patients with EE grades of C/D: adjusted OR = 0.06; CI 95% 0.02−0.18, p < 0.001. Follow-up endoscopy was performed by 44% of EE−C/D patients. Unmarried patients compared to married ones were less adherent (adjusted OR = 0.23; 95% CI 0.08−0.69, p < 0.001). Conclusions: Patients with esophagitis (EE−A/B) were more adherent to medical therapy when compared to patients with more severe esophagitis (EE−C/D).

Improving Patient Adherence to Lifestyle Changes for the Management of Gastroesophageal Reflux

Gastroesophageal reflux disease (GERD) is a common gastrointestinal illness with symptoms of heartburn, chest pain, and regurgitation. Management of GERD can involve medication use, lifestyle modification (eg, dietary modification), and surgical intervention depending on the individual patient and disease severity. Poor adherence to medication and recommended lifestyle changes may result in increased symptom severity and decreased quality of life. This paper aimed to systematically review the literature on lifestyle modification for the management of GERD. Fourteen articles were included based on search criteria. Following review and analysis, three types of lifestyle modifications were present in the literature and include medication use, dietary recommendations, and sleep recommendations. Despite being a pharmacological treatment, medication adherence was included in the review, as health behavior change can be used to improve adherence. Overall, the factors associated with adherence to modifications varied in terms of impact and directionality, depending on the type of lifestyle modification. Symptom severity emerged as important across all lifestyle modifications, and is associated with increased adherence to medication use, but decreased adherence to dietary guidelines. While patient-provider communication appeared to improve patient knowledge, it is unclear if increased knowledge translates to improved adherence. The review also demonstrated a lack of clear and standardized guidelines across lifestyle modifications, which may have an influence on adherence and adherence reporting. Future research in GERD treatment adherence would benefit from the use of validated measures to assess adherence. Specific recommendations to improving patient adherence are discussed.

Refractory Gastroesophageal Reflux Disease: A Management Update

Gastroesophageal reflux disease (GERD) is one of the most frequent gastrointestinal disorders. Proton pump inhibitors (PPIs) are effective in healing lesions and improving symptoms in most cases, although up to 40% of GERD patients do not respond adequately to PPI therapy. Refractory GERD (rGERD) is one of the most challenging problems, given its impact on the quality of life and consumption of health care resources. The definition of rGERD is a controversial topic as it has not been unequivocally established. Indeed, some patients unresponsive to PPIs who experience symptoms potentially related to GERD may not have GERD; in this case the definition could be replaced with “reflux-like PPI-refractory symptoms.” Patients with persistent reflux-like symptoms should undergo a diagnostic workup aimed at finding objective evidence of GERD through endoscopic and pH-impedance investigations. The management strategies regarding rGERD, apart from a careful check of patient's compliance with PPIs, a possible change in the timing of their administration and the choice of a PPI with a different metabolic pathway, include other pharmacologic treatments. These include histamine-2 receptor antagonists (H2RAs), alginates, antacids and mucosal protective agents, potassium competitive acid blockers (PCABs), prokinetics, gamma aminobutyric acid-B (GABA-B) receptor agonists and metabotropic glutamate receptor-5 (mGluR5) antagonists, and pain modulators. If there is no benefit from medical therapy, but there is objective evidence of GERD, invasive antireflux options should be evaluated after having carefully explained the risks and benefits to the patient. The most widely performed invasive antireflux option remains laparoscopic antireflux surgery (LARS), even if other, less invasive, interventions have been suggested in the last few decades, including endoscopic transoral incisionless fundoplication (TIF), magnetic sphincter augmentation (LINX) or radiofrequency therapy (Stretta). Due to the different mechanisms underlying rGERD, the most effective strategy can vary, and it should be tailored to each patient. The aim of this paper is to review the different management options available to successfully deal with rGERD.

No Associations Between Regular Use of Proton Pump Inhibitors and Risk of All-Cause and Cause-Specific Mortality: A Population-Based Cohort of 0.44 Million Participants

INTRODUCTION

The association between proton pump inhibitors' (PPIs) use and mortality remains unclear.

METHODS

This was a prospective analysis of 440,840 UK residents and 13,154 deaths. We evaluated the associations with multivariate Cox regression.

RESULTS

After adjusting for confounders, such as over health status and longstanding diseases, the regular use of PPIs was not associated with an increased risk of all-cause mortality and mortality due to neoplasms, circulatory system diseases, respiratory system diseases, digestive system diseases, external causes, and other causes.

DISCUSSION

Regular use of PPIs was not associated with an increased risk of all-cause and cause-specific mortality.

HISTORICAL PERSPECTIVE OF GASTROESOPHAGEAL REFLUX DISEASE CLINICAL TREATMENT

BACKGROUND

Gastroesophageal reflux disease (GERD) is one of the most prevalent gastrointestinal diseases. GERD generates significant impairment in patients' quality of life and it is associated to relevant medical resources utilization. A better understanding of GERD pathophysiology in the past five decades has favored the evolution of therapeutic strategies from non-drug interventions and antacids to more efficacious and safer alternatives.

OBJECTIVE

To summarize data about the historical evolution of GERD management in Brazil, focusing on medical therapy and addressing evidence on efficacy and safety of drug classes currently recommended.

METHODS

A narrative review was conducted by systematizing information about discoveries on GERD pathophysiology. We also addressed efficacy and safety of medications currently used to reduce symptoms and improve endoscopic healing of esophageal lesions. A structured search on Pubmed was performed to identify systematic reviews and meta-analysis investigating GERD outcomes positively impacted by proton pump inhibitors (PPIs), the first choice of pharmacotherapy for the disease.

RESULTS

The chronological development of therapeutic measures for GERD in Brazil evolved from lifestyle interventions with relative poor effect on symptoms related to esophageal acid exposure, particularly heartburn, to effective and safe pharmacological interventions such as histamine H2-receptor antagonists and PPIs. In the present days, some drug classes play a minor role in disease management, namely prokinetics and antacids, due to their reduced efficacy and relevant safety concerns (particularly with prokinetics). The main challenge for prescribers and researchers seems to be finding long-acting acid suppressants strategies able to ameliorate patients' symptoms and quality of life, thereafter, reducing medical resource consumption. The dual delayed-release PPI dexlansoprazole seems to respond for some of the limitations other PPIs have.

CONCLUSION

Recognizing the historical evolution of GERD management can help care providers to better understand therapeutic options for their patients, as well as focus on unmet needs that deserve further attention. PPIs are still the first choice therapy, with good evidence in favor of their efficacy, despite some safety concerns. However, as with any medical intervention, it is recommended to prescribe PPIs for patients with clear indication, using adequate dosing and monitoring for adverse events.

ARE THE PERSISTENT SYMPTOMS TO PROTON PUMP INHIBITOR THERAPY DUE TO REFRACTORY GASTROESOPHAGEAL REFLUX DISEASE OR TO OTHER DISORDERS?

BACKGROUND

Gastroesophageal reflux disease (GERD) is a clinical condition that develops when the reflux of stomach contents causes troublesome symptoms and/or complications. Transient lower esophageal sphincter relaxation is the main pathophysiological mechanism of GERD. Symptoms and complications can be related to the reflux of gastric contents into the esophagus, oral cavity, larynx and/or the lung. Symptoms and other possible manifestations of GERD are heartburn, regurgitation, dysphagia, non-cardiac chest pain, chronic cough, chronic laryngitis, asthma and dental erosions. The proton pump inhibitor (PPI) is the first-choice drug and the most commonly medication used for the treatment of GERD. The most widespread definition of Refractory GERD is the clinical condition that presents symptoms with partial or absent response to twice-daily PPI therapy. Persistence of symptoms occurs in 25% to 42% of patients who use PPI once-daily and in 10% to 20% who use PPI twice-daily.

OBJECTIVE

The objective is to describe a review of the current literature, highlighting the causes, diagnostic aspects and therapeutic approach of the cases with suspected reflux symptoms and unresponsive to PPI.

CONCLUSION

Initially, the management of PPI refractoriness consists in correcting low adherence to PPI therapy, adjusting the PPI dosage and emphasizing the recommendations on lifestyle modification change, avoiding food and activities that trigger symptoms. PPI decreases the number of episodes of acid reflux; however, the number of "non-acid" reflux increases and the patient continues to have reflux despite PPI. In this way, it is possible to greatly reduce greatly the occurrence of symptoms, especially those dependent on the acidity of the refluxed material. Response to PPI therapy can be evaluated through clinical, endoscopic, and reflux monitoring parameters. In the persistence of the symptoms and/or complications, other causes of Refractory GERD should be suspected. Then, diagnostic investigation must be initiated, which is supported by clinical parameters and complementary exams such as upper digestive endoscopy, esophageal manometry and ambulatory reflux monitoring (esophageal pH monitoring or esophageal impedance-pH monitoring). Causes of refractoriness to PPI therapy may be due to the true Refractory GERD, or even to other non-reflux diseases, which can generate symptoms similar to GERD. There are several causes contributing to PPI refractoriness, such as inappropriate use of the drug (lack of patient adherence to PPI therapy, inadequate dosage of PPI), residual acid reflux due to inadequate acid suppression, nocturnal acid escape, "non-acid" reflux, rapid metabolism of PPI, slow gastric emptying, and misdiagnosis of GERD. This is a common cause of failure of the clinical treatment and, in this case, the problem is not the treatment but the diagnosis. Causes of misdiagnosis of GERD are functional heartburn, achalasia, megaesophagus, eosinophilic esophagitis, other types of esophagitis, and other causes. The diagnosis and treatment are specific to each of these causes of refractoriness to clinical therapy with PPI.

Refractory Heartburn: A Challenging Problem in Clinical Practice

Gastroesophageal reflux disease (GERD) is a condition which develops when the reflux of stomach contents causes troublesome symptoms and/or complications. Heartburn and regurgitation are the typical symptoms of GERD. The treatment of GERD encompasses lifestyle modifications, pharmacological, endoscopic, and surgical therapy. The majority of the patients respond to 4-8 weeks of proton-pump inhibitors therapy, but 20-42% will demonstrate partial or complete lack of response to treatment. While these patients have been considered as having refractory heartburn, a subset of them does not have GERD or have not been adequately treated. The main causes of refractory heartburn include: poor compliance; inadequate proton-pump inhibitors dosage; incorrect diagnosis; comorbidities; genotypic differences; residual gastroesophageal reflux; eosinophilic esophagitis and others. Treatment is commonly directed toward the underlying cause of patients' refractory heartburn.

Construction, internal validation and implementation in a mobile application of a scoring system to predict nonadherence to proton pump inhibitors

BACKGROUND

Other studies have assessed nonadherence to proton pump inhibitors (PPIs), but none has developed a screening test for its detection.

OBJECTIVES

To construct and internally validate a predictive model for nonadherence to PPIs.

METHODS

This prospective observational study with a one-month follow-up was carried out in 2013 in Spain, and included 302 patients with a prescription for PPIs. The primary variable was nonadherence to PPIs (pill count). Secondary variables were gender, age, antidepressants, type of PPI, non-guideline-recommended prescription (NGRP) of PPIs, and total number of drugs. With the secondary variables, a binary logistic regression model to predict nonadherence was constructed and adapted to a points system. The ROC curve, with its area (AUC), was calculated and the optimal cut-off point was established. The points system was internally validated through 1,000 bootstrap samples and implemented in a mobile application (Android).

RESULTS

The points system had three prognostic variables: total number of drugs, NGRP of PPIs, and antidepressants. The AUC was 0.87 (95% CI [0.83-0.91], p < 0.001). The test yielded a sensitivity of 0.80 (95% CI [0.70-0.87]) and a specificity of 0.82 (95% CI [0.76-0.87]). The three parameters were very similar in the bootstrap validation.

CONCLUSIONS

A points system to predict nonadherence to PPIs has been constructed, internally validated and implemented in a mobile application. Provided similar results are obtained in external validation studies, we will have a screening tool to detect nonadherence to PPIs.

Fewer acute respiratory infection episodes among patients receiving treatment for gastroesophageal reflux disease

Patients with gastroesophageal reflux disease (GERD) present with comorbid complications with implications for healthcare utilization. To date, little is known about the effects of GERD treatment with a proton-pump inhibitor (PPI) on patients’ subsequent healthcare utilization for acute respiratory infections (ARIs). This population-based study compared ARI episodes captured through outpatient visits, one year before and one year after GERD patients received PPI treatment. We used retrospective data from the Longitudinal Health Insurance Database 2005 in Taiwan, comparing 21,486 patients diagnosed with GERD from 2010 to 2012 with 21,486 age-sex matched comparison patients without GERD. Annual ARI episodes represented by ambulatory care visits for ARI (visits during a 7-day period bundled into one episode), were compared between the patient groups during the 1-year period before and after the index date (date of GERD diagnosis for study patients, first ambulatory visit in the same year for their matched comparison counterpart). Multiple regression analysis using a difference-in-difference approach was performed to estimate the adjusted association between GERD treatment and the subsequent annual ARI rate. We found that the mean annual ARI episode rate among GERD patients reduced by 11.4%, from 4.39 before PPI treatment, to 3.89 following treatment (mean change = -0.5 visit, 95% confidence interval (CI) = (-0.64, -0.36)). In Poisson regression analysis, GERD treatment showed an independent association with the annual ARI rate, showing a negative estimate (with p<0.001). The study suggests that GERD treatment with PPIs may help reduce healthcare visits for ARIs, highlighting the importance of treatment-seeking by GERD patients and compliance with treatment.

Dexlansoprazole: delayed-release orally disintegrating tablets for the treatment of heartburn associated with non-erosive gastroesophageal reflux disease and the maintenance of erosive esophagitis

Gastroesophageal reflux disease (GERD) is a common condition afflicting millions of patients, whose prevalence continues to rise owing to the aging population and increasing burden of comorbid conditions, such as obesity. Currently, the mainstay of therapy for GERD is treatment with proton pump inhibitors (PPIs), which have proven efficacy, safety, and tolerability. Despite this, a considerable number of patients have refractory symptoms to PPI therapy. Dexlansoprazole is a new addition to the class of PPIs, which has a unique dual delayed drug release system, which aims to address the current limitations of acid suppressive therapy by offering extended acid suppression and improved ease of administration. Areas covered: This manuscript covers the pharmacokinetics, pharmacodynamics, clinical efficacy, and regulatory approval of dexlansoprazole. Additionally, there is further discussion concerning the current market settings and the potential future impact of dexlansoprazole. Expert commentary: Overall, dexlansoprazole offers benefits in its ease of administration and proven efficacy in the healing, maintenance of erosive esophagitis, and symptomatic non-erosive GERD. Long-term, dexlansoprazole will likely find a niche market among patients who fail other acid suppressive therapy or who desire simplified administration for compliance concerns, but will likely come at a higher out of pocket expense than comparable generic PPIs.

Gender differences in symptoms in partial responders to proton pump inhibitors for gastro-oesophageal reflux disease

BACKGROUND

Gender differences may exist in the symptom experience of patients with gastro-oesophageal reflux disease (GERD) who have a partial response to proton pump inhibitors (PPIs).

OBJECTIVE

The purpose of this study was to analyse gender differences in partial responders to PPIs.

METHODS

Patients with GERD who responded partially to PPIs (n = 580; NCT00703534) completed the Reflux Symptom Questionnaire 7-day recall (RESQ-7) and the Gastrointestinal Symptom Rating Scale (GSRS). Anxiety and depression were evaluated using the Hospital Anxiety and Depression Scale.

RESULTS

Women had significantly higher RESQ-7 domain scores than men for Heartburn (frequency: 4.3 vs 3.9; intensity: 3.1 vs 2.8), Burping (frequency: 4.9 vs 4.4; intensity: 3.1 vs 2.8) and Hoarseness, cough and difficulty swallowing (frequency: 2.6 vs 2.2; intensity: 1.8 vs 1.5), and had higher GSRS domain discomfort scores than men for Abdominal pain (3.51 vs 3.23), Indigestion (3.80 vs 3.45) and Constipation (2.69 vs 2.17) (all p < 0.05). Anxiety and depression were significantly more prevalent in women than in men.

CONCLUSION

In this population of partial responders, women had more frequent/intense heartburn and extra-oesophageal symptoms and more discomfort from abdominal pain, indigestion and constipation than men. Comorbid anxiety and depression may contribute to the increased symptom burden in women.

Respiratory physiotherapy in gastroesophageal reflux disease: A review article

Gastroesophageal reflux disease (GERD) is a frequent disorder which is expensive to diagnose and treat. Initiating therapy with empiric trial of proton-pump inhibitor is a well established strategy; however, symptoms of GERD do often persist regardless of effective medication. Nowadays, increasing interest concerning the efficacy and safety of chronic acid suppression with proton-pump inhibitors (PPIs), prompts a consideration for GERD treatment strategies related to the basic physiology of the lower esophageal sphincter, including modulation of its tone and ending of spontaneous transient lower esophageal sphincter relaxation, which contributes to reflux. Together, the lower esophageal sphincter and the crural diaphragm represent the major antireflux barrier, protecting the esophagus from reflux of gastric content. In order to prevent the need for enduring PPIs therapy or surgical procedures, substitute therapeutics approaches are being researched. Recently, studies have focused on the response of the respiratory muscles to inspiratory muscle training. As a result, inspiratory muscle training has emerged as a potential alternative for treatment of gastroesophageal reflux. The present report reviews the physiologic factors contributing to GERD, and presents the newly developed therapies that can be applied either alone or in association with available efficient GERD therapy.

Noncompliance is an impact factor in the treatment of gastroesophageal reflux disease

The basis of pharmacological treatment of the gastroesophageal reflux disease is the use of proton pump inhibitors (PPIs) which provide effective gastric acid secretion blockade. However, PPI therapy failure may occur in up to 42% of patients. The main causes for therapeutic failure are non-acid or weakly acid reflux, genotypic differences, presence of comorbidities, wrong diagnosis and lack of treatment compliance. Noncompliance is an important issue and should be carefully observed. Several studies addressed patient compliance and 20-50% of patients may present lack of compliance to the PPI prescribed. When symptoms persist depite adherence has been confirmed, it is recommended to substitute the prescribed PPI to another of the same class or alternatively, prescription of a double dose of the same drug. When even so the symptoms persist, other causes of failure should be assigned. In particular cases of PPI failure, fundoplication surgery may be indicated.

Refractory gastroesophageal reflux disease

CONTEXT

Gastroesophageal reflux disease (GERD) is a condition which develops when the reflux of stomach contents causes troublesome symptoms and/or complications. Its pathophysiology, diagnosis and treatment have frequently been analyzed but it is interesting to review some aspects of the GERD refractory patients to the proton pump inhibitors treatment. The treatment encompasses behavioral measures and pharmacological therapy. The majority of the patients respond well to proton pump inhibitors treatment but 20%-42% of them may not do so well. Patients who are unresponsible to 4-8 weeks' treatment with proton pump inhibitors (omeprazole, pantoprazole, rabeprazole, lansoprazole, esomeprazole, pantoprazole-Mg) might have so-called refractory GERD.

RESULTS

In some cases the patients are not real refractory because either they do not have GERD or the disease was not correctly treated, but the term refractory is still employed. Although debatable, the Brazilian GERD Consensus based upon evidences recommends as first step in the diagnosis, the upper digestive endoscopy to exclude the diagnosis of peptic ulcer and cancer and in some cases identify the presence of esophageal mucosa erosions.

CONCLUSIONS

The main causes of the so-called refractory GERD are: (1) functional heartburn; (2) low levels of adherence to proton pump inhibitors treatment; (3) inadequate proton pump inhibitors dosage; (4) wrong diagnosis; (5) co-morbidities and pill-induced esophagitis; (6) genotypic differences; (7) nonacid gastroesophageal reflux; (8) autoimmune skin diseases; (9) eosinophilic esophagitis.