Similarity and difference in the characteristics of eosinophilic esophagitis between Western countries and Japan

Abstract

Over the past two decades, the incidence and prevalence of eosinophilic esophagitis (EoE) have risen rapidly, especially in Western countries, with cases in Japan also showing a gradual increase in recent years. However, similarities and differences regarding the characteristics of EoE between Western countries and Japan remain to be clearly elucidated. The current clinical guidelines for diagnosis include symptoms related to esophageal dysfunction and dense eosinophilic infiltration in the esophageal epithelium. Most affected patients in Japan are diagnosed incidentally during a medical health check‐up and asymptomatic cases with typical endoscopic findings suggestive of EoE are frequently encountered. Clinical characteristics of EoE in Japanese are similar to those seen in Western populations. The predominant symptom is dysphagia, with food impaction extremely rare in Japanese cases. Linear furrows are the most frequently reported characteristic endoscopic finding, while an esophageal stricture or narrow caliber is rarely observed. Treatment strategies for EoE include drugs, dietary restrictions, and endoscopic dilation when the disease is advanced with stricture formation. Although single therapy using a proton‐pump inhibitor has been shown to achieve symptomatic and histological response in the majority of patients in Japan, no prospective randomized control studies that evaluated drug or elimination diet therapy have been presented. Overall, EoE has similar clinical characteristics between Japanese and Western populations, while disease severity seems to be milder in Japan. Additional studies are necessary to determine genetic factors, natural history of the disease, and treatment efficacy of drugs and elimination diet as compared to Western populations.

The role of advanced endoscopy in the management of inflammatory digestive diseases (upper gastrointestinal tract)

“…Considering this situation, the chances of EoE being diagnosed in Japan will increase, and its prevalence might not be much different from that in Western countries. Moreover, the characteristics of EoE in Asian patients were similar to those reported in Western patients while disease severity seems to be milder in Japan, 25 indicating a similar pathogenesis between Western and Asian patients. 28 Fujiwara analyzed symptoms in 886 EoE cases in Japanese adults and divided the symptoms into the following three categories: (i) typical symptoms, such as dysphagia (53%); (ii) other upper GI symptoms (40%); and (iii) no symptoms found during screening or medical examinations, i.e., "asymptomatic esophageal eosinophilia" (19%).…”

“…Although there are no detailed epidemiological data on EoE in Japan, its rate has steadily increased from 0.02% in 2011 to 0.34% in 2018, suggesting that EoE prevalence in Japan is gradually increasing. 25 A multicenter study published from Japan in 2020 showed a prevalence of EoE of 66 cases detected out of 130,013 upper endoscopic examinations (0.051%) (mean age, 45.2 years [range, 7-79 years]; 45 males). 26 On the other hand, a recent meta-analysis of population-based studies in Western countries showed a pooled prevalence of EoE of 34.4 cases per 100,000 inhabitants (95% CI, 23.1-47.5).…”

Pharynx and esophagus: Esophageal benign diseases

“…The most common symptom observed in Japanese patients is dysphagia, whereas few patients have a history of food impaction, which is frequently observed in Western patients. 12 Typical endoscopic findings include edema, rings, exudates, furrows, and strictures (Fig. 3), while there are several important issues with regard to such diagnosis of EoE.…”

“…By the late 1990s, EoE was increasingly recognized, and became commonly encountered in clinical and endoscopy situations, especially in Western countries. In Japan, EoE prevalence is gradually increasing, and its rate has steadily increased from 0.02% in 2011 to 0.34% in 2018 12 . The clinical characteristics such as responsiveness to PPI therapy in addition to essential findings for diagnosis are similar to Western populations, while disease severity seems to be milder in Japan.…”

“…The clinical characteristics such as responsiveness to PPI therapy in addition to essential findings for diagnosis are similar to Western populations, while disease severity seems to be milder in Japan. The most common symptom observed in Japanese patients is dysphagia, whereas few patients have a history of food impaction, which is frequently observed in Western patients 12 …”