Is there a seasonal variation in the incidence or intensity of allergic eosinophilic esophagitis in newly diagnosed children?

INTRODUCTION: Allergic eosinophilic esophagitis (AEE) is thought to be an allergic reaction that is characterized by inflammation caused by predominant accumulation of eosinophils in esophageal mucosa (> or =15 eosinophils per high power field). AIMS: To examine the seasonal distribution of newly diagnosed AEE children. METHODS: Retrospective analysis of all patients diagnosed with AEE at our institution over a nearly 6-year period (December 1998 to October 2004). RESULTS: Two hundred thirty-four children (mean age 7.3 y, median age 7.0 y, age range 0.2 to 19.5 y) were diagnosed with AEE during the study period. Significantly fewer patients were diagnosed with AEE in Winter as compared with Spring, Summer, and Fall. Although all the patients had severe eosinophilic esophagitis, the intensity of esophageal eosinophilia was less in Winter than in Summer or Fall, but not Spring, seasons. CONCLUSIONS: A seasonal variation was noted with Winter, a season of low outdoor allergens, having the fewest number of newly diagnosed AEE patients.