This study is being done to see if the investigators can use only the cytosponge ( A 10 minute, in office procedure that does not require sedation) to replace the 6-10 endoscopies routinely perform during dietary restriction and food reintroduction in EoE?

Dietary Therapy has been shown to be successful in the treatment of adult and pediatric patients with eosinophilic esophagitis Dietary studies were initially reported in children, but the results appear to be similar in adult patients. Elemental diets are successful in 70-95% of patients but are poorly tolerated. A six food elimination diet has been effective in about 70% of adult patients with EoE . In these adult studies skin prick testing was not helpful in predicting which foods would lead to a flare of disease when reintroduced into the diet. Therefore, the current standard of care requires multiple EGDs with esophageal biopsy during the dietary restriction and reintroduction phases of this study. Since the investigators are making lifelong dietary decisions during this process of food reintroduction, it is imperative the investigators be accurate. Unfortunately, these multiple EGDs have significant cost and are invasive procedures with some risk. Moreover, there is significant indirect costs with travel and time off work for the patients and drivers. Previous studies have found the esophageal sponge to be an accurate technique of accessing esophageal eosinophilia in EoE . The sponge is swallowed as a 12 mm capsule on a string. The capsule rapidly dissolves upon entering the stomach and the sponge then expands and can be pulled out the mouth five minutes after ingestion. In previous studies, the procedure was very well tolerated and all patients preferred the sponge to endoscopy.

Therefore the sponge is a well tolerated, inexpensive, very low risk procedure that would be an ideal option to replace EGD esophageal sampling in the evaluation of dietary treatment of EoE.

Inclusion Criteria:

• Diagnosed with Eosinophilic Esophagitis > than 15 Eos phf and failed to respond to the PPI therapy
• Going through the six food elimination diet or have just completed elimination the six foods: fish, nuts, eggs, soy, wheat, and milk

Exclusion Criteria:

• Clinical evidence of infectious process potentially contributing to dysphagia ( candidiasis, CMV, herpes)
• Other cause of dysphagia identified at endoscopy (e.g. reflux esophagitis, stricture, web, ring, achalasia, esophageal neoplasm)
• Esophageal minimal diameter < 13 mm on structured barium esophagram

Adverse Events were collected from baseline to end of study for approximately one year on all participants