Racial differences in eosinophilic gastrointestinal disorders among Caucasian and Asian

Background: Although there is an increasing number of eosinophilic gastrointestinal disorders (EGID) cases including eosinophilic esophagitis (EoE) and eosinophilic gastroenteritis (EGE), being reported globally, no systematic reviews have been conducted to elucidate the racial differences in these disorders. We aimed to show the racial differences, especially among Caucasians and Asians, in the risk of EoE and EGE. Methods: We conducted a systematic review using PubMed in September 2012. All case reports and case series on EGID that involved human subjects and described race or ethnicity, as well as pathological findings, were included. For the comparison of reported cases between Caucasians and Asians, a chi-squared test was used. Results: Among the 687 studies found in PubMed, 121 studies fulfilled the eligibility criteria. In total, 2621 patients were reviewed. Among Caucasian EGID patients, 94% had EoE; while among Asian EGID patients, 72% had EGE (p < 0.001). Among EoE, Asians were significantly less likely to have dysphagia and heartburn, but more likely to have vomit and abdominal pain, compared to Caucasians (p < 0.001). Further, among EGE, Asians were significantly more likely to have eosinophil-infiltrated colon than Caucasians (OR: 3.22, 95% confidence interval [CI]: 1.60-7.04), but were less likely to have eosinophil-infiltrated stomach (OR: 0.29, 95% CI: 0.17-0.49). Conclusions: We found that EoE occurs more frequently in Caucasian EGID patients than Asian EGID patients, while the reverse is true for EGE. Also, racial disparities in symptoms and eosinophil-infiltrated tissues were observed. Our findings suggest further genetic and environmental studies to elucidate the etiology of EGID. Copyright (C) 2015, Japanese Society of Allergology. Production and hosting by Elsevier B.V.