Background: Aeroallergens have been implicated in the pathogenesis of eosinophilic oesophagitis.
Aim: To determine whether a seasonal variation exists in the diagnoses of eosinophilic oesophagitis and whether there is a correlation with seasonal pollen count.
Methods: A retrospective review was performed from January 2006 to November 2008 to identify eosinophilic oesophagitis patients. Cases were classified by endoscopic date. Daily pollen counts for grass, trees and weeds were obtained from a certified counting station. Per cent of eosinophilic oesophagitis cases were collated seasonally and compared with mean pollen counts for grass, trees and weeds during the same time period.
Results: A total of 127 eosinophilic oesophagitis cases were identified (median age 41, range 19-92 years, 84% men). The highest percentage of cases (33.0%; Binomial P = 0.022) was diagnosed in the spring, while the least percentage (16%; Binomial P = 0.0.010) occurred in the winter. There was a significant association between per cent eosinophilic oesophagitis cases diagnosed seasonally and mean grass pollen count (r(s) = 1.000, P < 0.01), but not with trees (r(s) = 0.400, P = 0.600) or weeds (r(s) = 0.800, P = 0.200).
Conclusions: A seasonal variation was seen in the diagnosis of eosinophilic oesophagitis which correlated with pollen counts. These findings have important implications regarding the pathogenesis of eosinophilic oesophagitis, suggesting a potential role for aeroallergens.