Enterobius vermicularis in Paediatric Appendicectomy Patients in Far North Queensland, Australia: A Retrospective Study.

Background Enterobius vermicularis (E. vermicularis) is a common parasitic infection in children and is frequently identified incidentally in appendicectomy specimens. Its role in the pathogenesis of acute appendicitis remains controversial, with many cases demonstrating minimal or no appendiceal inflammation. Australian data describing the prevalence and clinical significance of E. vermicularis in paediatric appendicitis are limited. Methods A retrospective study was conducted of all patients aged <16 years who underwent appendicectomy at Cairns Hospital, a regional tertiary centre in Far North Queensland (FNQ), between January 2020 and December 2024. Demographic data, laboratory markers (white cell count {WCC} and C-reactive protein {CRP}), intraoperative findings and histopathology were extracted from electronic medical records. Intraoperative severity was graded using a four-level classification. Statistical analyses compared clinical and pathological features of E. vermicularis-positive cases. Results A total of 455 paediatric appendicectomies were performed during the study period. Of these patients, 370 cases (81%) had a positive histopathology for acute appendicitis. Enterobius vermicularis was identified in 45 specimens (9.9%). Among E. vermicularis-positive cases, 17 cases (37.8%) had a macroscopically normal appendix intraoperatively, and uncomplicated appendicitis was the most common operative impression (25 cases, 55.6%). Histopathology demonstrated acute inflammatory appendicitis in 19 out of 45 cases (42%) of E. vermicularis-positive specimens, while the remainder of the specimens were completely normal. Leucocytosis was present in 17 (37.8%) out of 45 cases, and C-reactive protein (CRP) was elevated in 26 (60.4%) cases, with CRP results unavailable for two patients. Conclusion Enterobius vermicularis was identified in approximately one in 10 paediatric appendicectomy specimens in Far North Queensland, a prevalence higher than that reported in most contemporary cohorts. The majority of E. vermicularis-positive cases lacked histological evidence of acute appendicitis, supporting the concept of appendiceal colic mimicking appendicitis. The routine postoperative review of histopathology is essential to ensure appropriate antiparasitic treatment and household management. The increased clinical awareness of parasitic mimics may help inform diagnostic decision-making and, if accompanied by appropriate blood tests and imaging, can reduce unnecessary surgery in selected low-risk children.