Low grade esophageal eosinophilia in adults: An unrecognized part of the spectrum of eosinophilic esophagitis?

Background: Eosinophilic esophagitis (EoE) is defined by a minimum of 15 eosinophils (eos) per high-powered field (HPF) on esophageal biopsy, along with esophageal symptoms and the exclusion of gastroesophageal reflux (GERD). The clinical significance of fewer eosinophils is unknown. Methods: Fifty-nine adult patients without a previous diagnosis of EoE with esophageal biopsies containing 1-14 eos per HPF (low grade eosinophilia) and 418 adult patients with ≥15 eos per HPF were identified by retrospective review. Patients were divided into group A (1-9 eos per HPF), group B (10-14 eos per HPF), and group C (≥15 eos per HPF) with a chart review of clinical and demographic data. Results: While dysphagia and atopy (asthma and allergic rhinitis) were more common in patients with ≥15 eos per HPF (group C) than those with low grade esophageal eosinophilia (groups A and B) (93 vs. 88%, P = 0.02), food impaction and heartburn occurred at an equal frequency across all patient groups. Endoscopic findings were likewise similar between groups. Of the 14 patients with low grade esophageal eosinophilia who underwent repeat endoscopy a mean interval of 42 weeks (range 8-118 weeks) later, five (36%) met conventional diagnostic criteria for EoE of 15 or greater eos per HPF. Follow-up in ten patients treated with topical corticosteroids noted improvement in nine, with mean follow-up of 8 weeks (range 4-12 weeks). Conclusion: Some adult patients with dysphagia and less than 15 eos per HPF have similar endoscopic findings and clinical course to patients meeting the consensus definition of EoE. Further evaluation of patients with low grade esophageal eosinophilia is needed.