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.