How are Patients Tested for Eosinophilic Esophagitis?

Diagnosis of eosinophilic esophagitis (EoE) is based on a patient’s symptoms communicated to the doctor and results of tests that are ordered. The tests also help the doctor to determine if the patient has EoE, a rare diagnosis, or if the patient might have gastroesophageal reflex disease (GERD), which is quite common.

The types of tests that are used for diagnosing EoE include:

• • Upper endoscopy: a tube with a light at the end is inserted through the mouth to directly see the lining of the esophagus. The doctor will be looking for signs of inflammation, rings/furrows in the lining, or areas that are narrow (Figure 2). During this endoscopy, the doctor will also take a few tissue samples from the esophageal lining that can be looked at under a microscope- a biopsy. The number of eosinophils in the tissue will be counted to help understand if a patient has EoE.

• Blood tests: tests that look for eosinophils, total immunoglobulin E (IgE), or specific IgEs in blood can help show whether or not an allergic process is involved in a patient’s symptoms.
• Esophageal sponge: a newer test that may be performed involves a patient swallowing a capsule containing a sponge on a string, which then expands in the stomach. As the string is pulled out of the esophagus, cells from the lining are taken with it and can be used to count eosinophils rather than endoscopy with a biopsy
• Allergy tests: as mentioned before, IgEs can be tested for in the blood, but this is not as useful for testing for EoE. Another type of test is a food patch test. Food is placed in a small chamber, a Finn chamber, and taped onto the patient’s back for 48 hours. Skin is then observed for signs of inflammation. Allergy tests can produce false positives, though, and are followed by food elimination diets to verify findings.

The endoscopy and biopsy may be repeated after beginning a new treatment to see if it has led to any changes in the lining of the esophagus.