The Evaluation of a Patient With Suspected EoE
Our series is on eosinophilic esophagitis (EoE) and I’ve covered how you present with this condition and a little bit about what the heck this condition really is! The website reference is http://www.medscape.com/viewarticle/754206?src=mp&spon=38
Patients with suspected EoE should be evaluated by both an allergist and a gastroenterologist.
- A careful history should include screening for the presence of reflux/GERD, growth delay, feeding/swallowing difficulty, and a past history of allergic disease.
- Symptoms of interest include history of weight loss or poor weight gain, dysphagia or odynophagia, multiple emergency department visits for impacted food, altered eating habits such as food aversions, overcutting or overchewing one’s food or eating very deliberately and requiring lots of fluids to wash down each bite.
- A family history of similar symptoms or atopy can also be a clue.
- EGD with multilevel biopsy is needed to make the tissue based diagnosis. Careful attention should be paid to gross features when performing the procedure. Dilation may frequently be performed in conjunction with the biopsy.
Allergen testing should be performed only in patients with biopsy proven EoE, because the tests do not have good positive predictive value without established disease. Unfortunately, skin testing can be positive AND negative in biopsy proven EoE, which leads to much confusion from a diagnostic standpoint.
Testing is guided by foods reported to cause symptoms, but should include 13 common foods with established predictive values for EoE. What are those foods? I’m glad you asked. Milk, egg, soy, wheat, corn, beef, chicken, apple, rice, potato, peanut, oat, barley. This means BOTH skin testing and patch tests to the above list. Patch testing is a bit different in that I make a ”paste” with the food and place it in a Finn chamber on the back for 48 hours. Keeping it on can be a challenge, but good results.
Patch test applied to skin
Loading a Finn chamber for patch testing
Inhalants should also be tested given aeroallergy can play a role. Food atopy patch testing assesses for a cellular-mediated mechanism, and should be placed for food items not positive on initial testing, and read at a minimum of 48 hours after placement. Both prick and patch tests have independent positive and negative predictive values, as well as combined values. Foods positive on either test are generally recommended to be removed from the diet. There is no established role for ImmunoCAP® testing or other allergy blood tests in diagnosing EoE.
- So there you have it…find out if EoE is even present before testing for foods.
- Use both skin tests and patch testing to identify suspected foods that will need to be eliminated.
- And in case you’re wondering, here’s what a positive patch test looks like…..
Positive patch test for EoE.