Association between atopic manifestations and eosinophilic esophagitis: A systematic review and meta-analysis

Eosinophilic esophagitis (EoE) has repeatedly been associated with atopic manifestations, which are reported more frequently in these patients than in the general population. To systematically assess the evidence and strength of the associations between EoE and atopy. We performed a systematic search of the MEDLINE, EMBASE, and SCOPUS databases for case-control studies comparing the frequency of atopic diatheses among patients with EoE and control subjects representing the general population without EoE. Using random-effects meta-analyses, we calculated summary estimates, including 95% confidence intervals (CIs), for bronchial asthma, atopic rhinitis, and eczema. Publication bias risks were assessed by means of funnel plot analysis and specific statistical tests. Of the 2,954 references identified, data were collected from 21 studies, including a total of 53,542 patients with EoE and 54,759 controls. The criteria for defining a diagnosis of atopy in patients with EoE or controls was not structurally considered in most of the studies. Overall, allergic rhinitis was significantly more common among patients with EoE compared with control subjects (odds ratio [OR], 5.09; 95% CI, 2.91-8.90; I(2) = 86.7%) as were bronchial asthma (OR, 3.01; 95% CI, 1.96-4.62; I(2) = 84.5%) and eczema (OR, 2.85; 95% CI, 1.87-4.34; I(2) = 57.1%). Food allergies and other atopic conditions were also assessed. No significant publication bias was found for studies dealing with allergic rhinitis and eczema in EoE. Despite pointing to a significant association between atopy and EoE, most of the studies provided no normalized diagnostic criteria for atopy. Further research should provide clear and standardized definitions of such conditions. www.crd.york.ac.uk/PROSPERO Trial Identifier: CRD42016036161