Seasonal variations in the occurrence of acute appendicitis and their relationship with the presence of fecaliths in children

BACKGROUND: Acute appendicitis (AA) is the most common surgical condition in children. Although a higher incidence of AA in summer has been reported, the reason for this observation remains unclear. The purpose of this study was to compare the clinical findings of AA patients who underwent appendectomies during the summer months with those who underwent the procedure during the non-summer months. METHODS: The clinical data of 171 patients who underwent appendectomy from January 2013 to December 2016 were reviewed. The patients were divided into a summer group (from May to October) and a non-summer group (from November to April) based on the month when appendectomy was performed. All patients were under 18 years of age at the time of surgery. The medical records including laboratory data, computed tomography scans, pathology reports and operative notes were reviewed. RESULTS: The number of patients with AA was higher in the summer group than in the non-summer group (101 vs. 70 patients). No significant differences in the laboratory results between the two groups of patients were observed. The percentage of AA patients who presented with a fecalith was significantly lower in the summer group (33.6%) than in the non-summer group (55.7%). No significant differences in the incidence of appendiceal perforations and abscesses, as well as postoperative complications were observed between the two groups. CONCLUSIONS: The percentage of AA patients with fecaliths in summer was lower than that in the non-summer months. The increase in the number of AA patients in summer may be due to the increased occurrence of lymphoid hyperplasia, which may be correlated with the yearly outbreak of enterovirus infection during this period.