Epidemiology and Risk Factors of Eosinophilic Esophagitis in Japan: A Population-Based Study

Endoscopic diagnosis and management of eosinophilic esophagitis

Eosinophilic esophagitis is a chronic allergic inflammatory disease, and its incidence and prevalence have recently increased. Eosinophilic esophagitis has not become a rare disease; thus, knowledge for diagnosing it is needed in current clinical practice. The adequate management of endoscopic procedures is particularly important for the diagnosis and evaluation of inflammatory activity and therapeutic responses. The therapeutic options for eosinophilic esophagitis include anti-acid drugs such as proton pump inhibitors, potassium-competitive acid blockers, swallowed topical corticosteroids, biologics, and dietary elimination therapies. Moreover, endoscopic esophageal dilation is a therapeutic option for fibrotic strictures due to eosinophilic esophagitis to improve obstructive symptoms, such as dysphagia and food impaction. In this review, we describe the endoscopic characteristics of eosinophilic esophagitis, including an endoscopic reference score and an optimal biopsy protocol to diagnose and evaluate the therapeutic response. We also describe a current therapeutic management of eosinophilic esophagitis.

Epidemiology and risk factors of non-esophageal eosinophilic gastrointestinal diseases in Japan: A population-based study

BACKGROUND

Non-esophageal eosinophilic gastrointestinal diseases (non-EoE EGIDs) are allergic conditions where Th-2-predominant inflammation causes symptoms related to gastrointestinal tract dysfunction. No studies have reported the incidence of non-EoE EGIDs. In addition, little is known about the influence of lifestyle factors on the condition.

METHODS

We used a large health claim database from January 2005 to September 2022. Non-EoE EGIDs cases were identified on the basis of the International Classification of Diseases-tenth Revision code, K52.8. The incidence and prevalence of non-EoE EGIDs were estimated by Poisson and binomial distribution, respectively. For each case, 10 controls were randomly selected for a nested case-control study to identify potential risk factors of non-EoE EGIDs.

RESULTS

Of 15,200,895 individuals, 1,368 new cases of non-EoE EGIDs were identified. The incidence and prevalence of non-EoE EGIDs in 2022 were 3.07 (95% CI 2.67-3.52) per 100,000 person-years and 17.23 (95% CI 16.38-18.11) per 100,000 individuals, respectively, which were approximately 6 and 9 times higher than those in 2010. Allergic rhinitis (OR 1.63 (95% CI 1.16-2.29), p = 0.005), chronic sinusitis (OR 2.41 (95% CI 1.58-3.66), p < 0.001), and urticaria (OR 2.32 (95% CI 1.45-3.70), p < 0.001) were related to an increased risk of adult non-EoE EGIDs. Whilst atopic dermatitis (OR 2.28 (95% CI 1.35-3.86), p = 0.006) and the perinatal factors (OR 3.68 (95% CI 1.13-12.02), p = 0.031) were associated with an increased risk of pediatric non-EoE EGIDs. No association was seen with lifestyle factors such as obesity, smoking and alcohol consumption.

CONCLUSIONS

The incidence and prevalence of non-EoE EGIDs have increased over the past two decades.

Prevalence and Costs of Eosinophilic Esophagitis in the United States

BACKGROUND & AIMS

Eosinophilic esophagitis (EoE) has been continually increasing in prevalence, but current estimates are lacking. We aimed to determine updated estimates of the prevalence and medical costs associated with EoE in the United States (U.S.).

METHODS

We used two large administrative databases, MarketScan and Medicare, and International Classification of Disease codes to calculate annual prevalence of EoE, as well as age- and sex-stratified estimates, standardized to the U.S.

POPULATION

Health care utilization, including medications and endoscopic procedures, was quantified, and annual EoE-associated costs were estimated.

RESULTS

We identified 20,435 EoE cases in MarketScan in 2022 and 1913 EoE cases in Medicare in 2017. This translated to prevalences of 163.08 cases/100,000 and 64.83 cases/ 100,000 in MarketScan and Medicare, respectively. There was a 5-fold increase in prevalence in both databases since 2009. In MarketScan, prevalence was higher among males (204.45/100,000 vs 122.06/100,000 among females); for both sexes, peak prevalence was from 40 to 44 years of age. Standardized to the U.S. population, the prevalence of EoE was 142.5/100,000, extrapolating to 472,380 cases. Total EoE-associated health care costs were estimated to be $1.32 billion in 2024 dollars after accounting for inflation.

CONCLUSIONS

The prevalence of EoE continues to increase, with a rate of 1 in 617 in 2022 in those <65 years of age, and 1 in 1562 in 2017 those ≥65 years. Standardized to the U.S. population, the overall prevalence was approximately 1 in 700. EoE-associated annual costs were estimated to be $1.3 billion in 2024 dollars, representing a substantial financial burden.

Real world treatment patterns in patients with eosinophilic esophagitis in Japan

The management of eosinophilic esophagitis (EoE) has not been completely established yet. There is a controversy over the universal maintenance therapy for EoE to prevent esophageal fibrostenotic complications. Using an employer-based insurance claim database from January 2005 to September 2022, we investigated the treatment patterns of EoE and the occurrence of esophageal complications. The treatment patterns were analyzed at a 6-month interval from the diagnosis of EoE. The time to treatment discontinuation of proton pump inhibitor (PPI)/potassium-competitive acid blocker (P-CAB) was evaluated by the Kaplan-Meier method. Of 15,200,895 individuals, 615 patients with EoE were ultimately analyzed with the median follow-up time from the index date of 700 days. PPI/P-CAB and swallowed topical steroids accounted for 80% and 4.6% of the initial therapy, respectively. PPI/P-CAB use rapidly decreased by 40% in the first 6 months and afterwards reinitiation was rarely seen. The median time to treatment discontinuation were 172 days (95% CI 147-206 days) for PPI/P-CAB. Only 1 EoE patient developed esophageal fibrostenotic complications after the diagnosis. With the low incidence of esophageal complications, the universal maintenance therapy may not be necessary for mild EoE patients often seen in Japan.

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.