Seasonal exacerbation of eosinophilic esophagitis histologic activity in adults and children implicates role of aeroallergens.

Background: Disease activity may correlate with environmental aeroallergen exposure in eosinophilic esophagitis. The association between seasons and flares of eosinophilic esophagitis (EoE) histologic activity has not been extensively studied.

Objective: We aimed to assess the frequency of seasonal exacerbations of eosinophilic esophagitis, as well as changes in symptom reporting, endoscopic findings, and histologic findings attributed to aeroallergens in an EoE cohort.

Methods: In this retrospective cohort study, we analyzed EoE patients in histologic remission (<15 eosinophil/high-power field) but who doubled the esophageal eosinophil count between seasons without change in eosinophilic esophagitis-specific therapy. Outcomes were: symptomatic global worsening (yes/no); change in endoscopic severity (EREFS scoring system); and histologic change (peak eosinophil count).

Results: Of 782 patients, 13 (4%) met inclusion criteria (mean age: 36.2; 85% male; 86% white; 85% atopic disease diagnosis), and 14 exacerbations were recorded. Of these, 71% occurred in fall and summer months. Peak eosinophil counts increased from 6.8 to 86.8 eosinophil per high-power field (P < .001). Four patients (31%) reported worsening of seasonal allergies and 5 (38%) a global worsening of symptoms. Endoscopic severity was also significantly worse during seasonal exacerbations (total EREFS 3.7 vs 1.7; P = .01). Baseline features differed by atopic diagnoses and endoscopic findings between patients with and without seasonal exacerbations.

Conclusion: Seasonal exacerbations of eosinophilic esophagitis were uncommon in this cohort and most commonly recorded over the summer and fall months. These data support a role of aeroallergens in the pathogenesis of eosinophilic esophagitis in some patients, and clinicians should consider aeroallergens as a potential cause of disease exacerbation.