Esophageal String Test Monitoring to Monitor Eosinophilic Esophagitis During Oral Immunotherapy

Inclusion Criteria: An individual must meet all of the following criteria: * Male or female, aged 7 to 18 years old, inclusive * Have a history of Immunoglobulin (IgE)-mediated food allergy * Considering using oral immunotherapy (OIT) for food allergies at CHOP° * Able \& willing to swallow the esophageal capsule * Parental/guardian permission (informed consent) and if appropriate, child assent. * Willing to comply with all study procedures and be available for the duration of the study. Exclusion Criteria: * Known or expected need for MRI imaging during the study period * Known connective tissue disease * Known eosinophilic disorder including any eosinophilic gastrointestinal disorder and hypereosinophilic disorder * Past history of caustic ingestion or other esophageal injury * History of esophageal surgery or dilation (i.e.: tracheoesophageal fistula repair) * History of gastrointestinal motility disorder including esophageal achalasia * History of inflammatory bowel disease * Unwilling or unable to swallow the EST * Oral or intravenous steroids in the preceding 60 days (not including swallowed topical fluticasone, budesonide, etc.) * Participation in a clinical study that may interfere with participation in this study * Pregnant or lactating females * Limited English proficiency * Parents/guardians or subjects who, in the opinion of the Investigator, may be non-compliant with study schedules or procedures.