RecruitingDevice studyEsophageal String Test Monitoring to Monitor Eosinophilic Esophagitis During Oral ImmunotherapyPatients with IgE mediated food Allergy have elevated risk of eosinophilic esophagitis, and new therapies like oral immunotherapy (OIT) carry additional risk of Eosinophilic Esophagitis (EoE). The goal of this study is to investigate the Esophageal String Test (EST) as a screening tool for Eosinophilic Esophagitis (EoE) during OIT therapy. Investigators will compare the efficacy of the Esophageal String Test to symptom assessment using a validated patient reported symptom questionnaire, the Pediatric Eosinophilic Esophagitis Symptom Score (PEESS) v2.0. Investigators will utilize these tools to screen patients at their baseline visit prior to the start of OIT, then at the 3- and 6-month OIT follow-up visits.