P132 Six-food elimination diet is less effective during pollen season in adult patients with eosinophilic esophagitis sensitized to pollens

Background & Aims

The role of inhaled and subsequently swallowed aeroallergens in treatment outcomes of adults with eosinophilic esophagitis (EoE) is unclear. We hypothesized that the pollen season contributes to the failure of dietary therapy in EoE. In this international two-centre study, we compared six-food elimination diet (SFED) outcomes of EoE patients assessed on- versus off- pollen season.

Methods

Consecutive adult patients (≥18 years) with EoE who underwent SFED and skin prick test (SPT) for birch and grass pollen were included. Demographics, atopy, SPT results, endoscopy findings (EREFS), and the date of the endoscopy following SFED were retrospectively extracted. Individual sensitization profiles and historical pollen count data were scrutinized to define whether each patient had been assessed on or off pollen season following SFED. For patients without pollen sensitization, Spring (March, April, May) was considered as on-pollen season for comparison purposes. Patients were divided into group A (positive SPT for pollens) or B (negative SPT for pollens). All patients had active EoE before SFED (eosinophils ≥15/high-power field, HPF) and adhered to SFED under the supervision of a dietitian. Response to SFED (eos<15/HPF) was assessed after a minimum of 6 weeks. Data are described as median/interquartile range (Q1-Q3) or as counts/percent. Kruskal-Wallis Rank Sum Test, Pearson’s Chi-Square and Fisher’s exact test were used as appropriate. Significance threshold was p<0.05.

Results

Fifty-eight patients were included, 62.0% had positive SPT for grass and/or birch (group A), while in 37.9% SPT was negative (group B). Significantly more patients from group A also had positive SPT for dust mite, cat and/or dog dander (85.7% vs 31.8%, p<0.001). The two groups were comparable in sex, age, baseline symptoms, atopy, baseline EREFS, and duration of SFED. The overall SFED response was 56.9%, (95% CI, 44.1%-68.8%) regardless of SPT results and pollen season. When stratifying SFED response according to whether the assessment of the efficacy had been performed on or off pollen season, patients sensitized to pollens showed significantly lower response to SFED when the assessment was performed on compared to off pollen season (21.4% vs 77.3%; p=0.003). Additionally, on pollen season, patients with positive SPT for pollens had significantly lower response to SFED compared to those with negative SPT (21.4% vs 77.8%; p=0.01). Patients without pollen sensitization did not show seasonal variations in SFED response (66.7% vs 53.8%; p=0.67) (table 1).

Conclusion

Pollens may have a role in sustaining esophageal eosinophilia in sensitized adults with EoE despite avoidance of trigger foods. SPT for pollens may have a clinical utility in the dietary management of EoE by identifying patients less likely to respond to SFED during pollen season.