453:
Skin Testing with Different Food Formulations in an Eosinophilic Esophagitis Population
Sunday, March 4, 2018
South Hall A2 (Convention Center)
Jennifer Miller, MD, Christopher Frey, BS, Charles Minard, PhD, Jessica Lee, BS, Munazza Noor, MS, Anthony Olive, MD, Carla M. Davis, MD FAAAAI, Sara Anvari, MD, MSc
RATIONALE: Eosinophilic Esophagitis (EoE) is caused by a mixed type I and IV hypersensitivity immune mechanism. Prick skin testing (PST) and atopy patch testing (APT) can detect potential food triggers, but generalizability is limited by the need for fresh foods. We compared the PST and APT for fresh, powder and extract forms of milk, egg, soy and wheat in pediatric patients with EoE.

METHODS: This was a pilot study, including 25 patients with biopsy proven EoE. A pairwise comparison of fresh, powder and extract for milk, egg, soy and wheat was performed on PST wheal size and APT inflammation score by Wilcoxon signed rank test and with Holm step-down Bonferroni method adjustment for multiple hypothesis testing.

RESULTS: Fresh and powder APT were consistently more inflamed than extract. A statistical difference (unadj p<0.05) in the level of inflammation between fresh-extract and powder-extract was observed on APT for all foods. Adjusted p-values demonstrated a difference between fresh and extract APT for milk, soy and wheat (adj p<0.05) indicating that fresh was more likely to show positive score than extract. The comparison between powder and extract was only significant for wheat (adj p=0.02). No differences were observed for PST pairwise comparisons.

CONCLUSIONS: The comparison of PST and APT testing for fresh, powder and extract foods in EoE shows similarity between fresh and powdered foods. Food extracts cause less inflammation than fresh or powder APT. APT with food powders may be a viable option to determine targeted elimination diets, but further testing is required to validate these results.