Systematic review: Eosinophilic esophagitis in Asian countries

Abstract

Aim: To investigate the prevalence and the clinical characteristics of Asian patients with eosinophilic esophagitis.

Methods: We conducted a systematic search of the PubMed and Web of Science databases for original studies, case series, and individual case reports of eosinophilic esophagitis in Asian countries published from January 1980 to January 2015. We found 66 and 80 articles in the PubMed and Web of Science databases, respectively; 24 duplicate articles were removed. After excluding animal studies, articles not written in English, and meeting abstracts, 25 articles containing 217 patients were selected for analysis.

Results: Sample size-weighted mean values were determined for all pooled prevalence data and clinical characteristics. The mean age of the adult patients with eosinophilic esophagitis was approximately 50 years, and 73% of these patients were male. They frequently presented with allergic diseases including bronchial asthma, allergic rhinitis, food allergy, and atopic dermatitis. Bronchial asthma was the most frequent comorbid allergic disease, occurring in 24% of patients with eosinophilic esophagitis. Dysphagia was the primary symptom reported; 44% of the patients complained of dysphagia. Although laboratory blood tests are not adequately sensitive for an accurate diagnosis of eosinophilic esophagitis, endoscopic examinations revealed abnormal findings typical of this disease, including longitudinal furrows and concentric rings, in 82% of the cases. One-third of the cases responded to proton pump inhibitor administration.

Conclusion: The characteristics of eosinophilic esophagitis in Asian patients were similar to those reported in Western patients, indicating that this disease displays a similar pathogenesis between Western and Asian patients.

Keywords: Allergy; Asia; Endoscopy; Eosinophilic esophagitis; Prevalence; Symptom; Treatment.

Figure 1

Flow chart of our systematic literature search.

Figure 2

Number of patients with eosinophilic esophagitis in all 25 studies included in this review. The dots indicate the mean age, and the dot size indicates the number of patients. One report did not describe the ages of the included patients.

Figure 3

Reported prevalence of eosinophilic esophagitis in patients examined via upper gastrointestinal endoscopy. In the studies using a smaller sample size, the prevalence of eosinophilic esophagitis (EoE) was higher. Different indication criteria for endoscopic examination between institutions may be partially responsible for the large variation in the reported incidence of EoE.

Figure 4

Allergic diseases reported by patients with eosinophilic esophagitis. Twenty-one articles contained descriptions of the histories of allergic diseases among the reported patients. The most frequently reported allergic disease was bronchial asthma, followed by allergic rhinitis.

Figure 5

Symptoms reported by patients with eosinophilic esophagitis. Twenty-four articles contained descriptions of symptoms reported by patients. The most frequently reported symptom was dysphagia, followed by heartburn.

Figure 6

Endoscopic abnormalities found in patients with eosinophilic esophagitis. Longitudinal furrows, white plaques, and fixed/transient concentric rings were most frequently detected.