title: Seasonal distribution of initial diagnosis and clinical recrudescence of eosinophilic esophagitis: a systematic review and meta-analysis.
abstract: 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.
authors.affiliation: Department of Gastroenterology, Hospital General de Tomelloso, Tomelloso, Spain.
authors.forename: A J
authors.initials: AJ
authors.lastname: Lucendo
authors.affiliation: Research Unit, Complejo Hospitalario La Mancha Centro, Alcázar de San Juan, Spain.
authors.forename: Á
authors.initials: Á
authors.lastname: Arias
authors.affiliation: Research Unit, Complejo Hospitalario La Mancha Centro, Alcázar de San Juan, Spain.
authors.forename: O
authors.initials: O
authors.lastname: Redondo-González
authors.affiliation: Department of Allergy, Hospital General de Tomelloso, Tomelloso, Spain.
authors.forename: J
authors.initials: J
authors.lastname: González-Cervera
mesh_terms: D057765:Eosinophilic Esophagitis / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D015995:Prevalence; D012008:Recurrence; D012621:Seasons
keywords: eosinophilic esophagitis; meta-analysis; pollen; season; systematic review