Background: The association between seasonality and diagnosis and/or recrudescence of eosinophilic esophagitis (EoE) remains unclear, with some studies demonstrating a higher diagnostic rate in those months with a higher aeroallergen load while others rule out this association.
Methods: We performed a systematic search of the MEDLINE, EMBASE, and SCOPUS databases for studies on the seasonality of the initial diagnosis or recrudescence (i.e., food bolus impaction) of EoE. Summary estimates, including 95% confidence intervals, were calculated for seasonal variation in diagnosis or incidence of food bolus impaction. A random-effects meta-regression model was made using aggregate-level data to compare seasonality in EoE diagnosis and recrudescence. Publication bias risks were assessed by means of funnel plot analysis.
Results: Of 1078 references found, data were finally collected from 18 studies which included a total of 16,846 EoE patients. Of all new cases of EoE diagnosed per year, 27.1% were diagnosed in spring and 21.5% in winter. No overall statistical differences in the annual seasonal distribution of newly diagnosed EoE cases were observed in the random-effects meta-regression model (P = 0.132). Similarly, a homogenous distribution of episodes of EoE recrudescence throughout the year was noted, with no significant differences between seasons (P = 0.699). No significant publication bias was found.
Conclusions: This systematic review found no significant variations in the seasonal distribution of either the diagnosis or clinical recrudescence of EoE throughout the year.
Keywords: eosinophilic esophagitis; meta-analysis; pollen; season; systematic review.
© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.