Efficacy of Atopy Patch Testing in Directed Dietary Therapy of Eosinophilic Esophagitis: A Pilot Study

Background Atopy patch testing (APT) has shown potential for predicting dietary food triggers in studies of children and adolescents with eosinophilic esophagitis (EoE). Aims To assess the efficacy of APT in adults with EoE. Methods We conducted a prospective open-label pilot study of patients >= 18 years old with diagnosis of EoE at Mayo Clinic in Rochester, Minnesota, from November 2014 to January 2016. All patients underwent patch testing using intact food products, followed by a six food elimination diet and stepwise food reintroduction. Response to elimination diet was assessed with serial endoscopy with biopsies as well as clinical symptoms. APT results were directly compared to elimination diet results for assessment of efficacy. Correlation between clinical symptoms, endoscopic score, and histology was also qualitatively evaluated. Results Fifty percent of the patients had a positive APT, while only 16% had an APT result confirmed histologically during food reintroduction. Sensitivity of APT was calculated to be 5.9%, with specificity of 92.0%. Furthermore, we found significant qualitative inter-patient heterogeneity in the correlation between clinical symptoms, EREFS score, and histology. Conclusions APT does not reliably predict food triggers identified by food elimination diet in adult patients with EoE. As a result, APT does not have a clear role in the evaluation of patients with EoE.