Seasonal Variations in the Incidence of Acute Appendicitis

Abstract

Although acute appendicitis (AA) occurs throughout the year, seasonal variations have been reported. Some papers point out that high atmospheric pressure cause a increase of inflammatory diseases. We aimed to examine whether particular months are associated with a higher incidence of AA. We reviewed electronic medical records and analyzed the data of all patients with a diagnosis of AA from 2012 to 2014 who underwent appendectomies. We included 450 patients (mean age, 38.3 years ; 60% men). The number of appendectomies per month was examined, and the variation was revealed to have statistical significance. The incidence of AA was significantly higher in July, August, and September than in November and December (p<0.05). Atmospheric temperature may correlate with this variability, while it is unlikely that atmospheric pressure will be correlated. Although the reasons for this variability remain unknown, this information may contribute to understanding the cause of appendicitis.