The Rising Incidence of Eosinophilic Oesophagitis Is Associated With Increasing Biopsy Rates

A Population-Based Study

A. A. N. Syed; C. N. Andrews; E. Shaffer; S. J. Urbanski; P. Beck; M. Storr

Disclosures

Aliment Pharmacol Ther. 2012;36(10):950-958. 

In This Article

Abstract and Introduction

Abstract

Background Eosinophilic oesophagitis (EoE) has evolved from a supposedly rare entity to one whose incidence rates are approaching that of inflammatory bowel disease. The factors responsible for this apparent increase in the incidence remain obscure.
Aim To assess various endoscopist and pathologist factors that might affect the frequency of EoE being detected in a well-defined North American population.
Hypothesis Increased endoscopist and pathologist awareness has contributed to the increased clinical recognition of EoE.
Methods Cases of EoE were identified systematically using population-based pathology and endoscopy databases from January 2004 to December 2008 in Calgary, Canada (population 1.25 million). EoE frequency was estimated with time trend analysis. Characteristics of individual endoscopists (n = 45) were compared with diagnostic rates.
Results Crude population incidence of EoE increased from 2.1 per 105 in 2004 to 11.0 per 105 in 2008: an annual increase of 39% (P < 0.0001). The frequency in men was 4.5 times higher than in women (95% CI: 3.51–5.76). In patients presenting with dysphagia oesophageal biopsy rates increased from 17.0% in 2004 to 41.3% of EGDs in 2008: an annual rise of 26% (P < 0.0001). On multivariate regression analysis, those endoscopists with higher biopsy rates were more likely to make the diagnosis of EoE (P = 0.008). To include or exclude the diagnosis, typical histological features of EoE were reported more often by pathologists in 2008 as compared to 2004 (P = 0.01 & P < 0.0001 respectively).
Conclusions The incidence of eosinophilic oesophagitis continues to rise in the general population, in part due to increasing oesophageal biopsy rates and a more detailed histological evaluation of specimens. The biopsy rate of an endoscopist is an indicator for a higher diagnostic yield.

Introduction

Eosinophilic oesophagitis (EoE) has evolved over the last 15 years from a rare entity to one whose incidence rates are approaching that of inflammatory bowel disease. It is now recognised as one of the most common causes of dysphagia and recurrent food bolus impaction necessitating urgent endoscopic intervention.[1–8] The histological hallmark of EoE is a dense intraepithelial eosinophilic infiltrate.[9] This eosinophilic inflammation is thought to be responsible for the characteristic endoscopic features, like white surface exudates, linear furrowing, multiple concentric rings (trachealisation) and narrow calibre oesophagus.[6,10–14] Even though the diagnostic criteria for EoE are still in development, the most consistent finding is oesophageal mucosal biopsy specimens containing ≥15 intraepithelial eosinophils per high powered field (400×) in a patient with symptoms of dysphagia, recurrent food bolus impaction and/or refractory gastro-oesophageal reflux disease (GERD).[2,4,15–17] The pathogenesis of EoE seems to involve genetic and environmental factors. Due to the association with various allergic disorders an atopic mechanism has been postulated. Indeed, most patients with symptomatic EoE improve on allergen-free diet or with the use of corticosteroids.[18–27,37]

Recent reports indicate a dramatic upsurge in the frequency of EoE in both paediatric and adult populations.[7,28–31] A prospective study of adult patients with EoE conducted in a geographically stable area of Europe suggests a true rise in incidence.[30] Similar trends were observed in paediatric patients.[28,29] It remains controversial, however, whether this is a true increase in the incidence or merely a phenomenon of heightened recognition. Support for the latter comes from a histopathological study in which oesophageal biopsies taken from consecutive patients in 2005, when compared with biopsies from a similar group of consecutive patients in 1990, showed no difference in the frequency of EoE. This implies that the apparent increase in the incidence of eosinophilic oesophagitis is largely the result of increased recognition rather than an increase in disease frequency.[32]

To date, no population-based study has evaluated variables that might account for this apparent increase in the incidence of EoE. We therefore assessed various endoscopist and pathologist factors that might affect the frequency of EoE being detected in a well-defined North American population.

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