Eosinopenia as an Independent Predictor of Complicated Acute Appendicitis: Usefulness in Adults, Not in Children

Background. The role of eosinophils in acute appendicitis (AA) is not well known. The aim of this study is to analyze whether peripheral blood eosinophil concentration can be useful in predicting episodes of complicated AA among pediatric and adult populations.Methods. A retrospective cohort study was conducted in patients with a clinical diagnosis of AA confirmed by histopathological findings. Receiver Operating Characteristic (ROC) curve analysis and multivariate models were performed.Results. A total of 531 cases were included (43.7% children). Complicated AA was present in 31.5% of children and 34.4% of adults. Symptom duration among children were ≥36 hours (aOR 2.24, p = 0.006) and a neutrophil to lymphocyte ratio (NLR) ≥4.7 (aOR 3.63, p = 0.006) increased the likelihood of complicated AA. In adults, eosinophil concentration <40 cells/µL (aOR 1.88, p = 0.033), being male (aOR 2.53, p < 0.001), and having a NLR ≥4.7 (aOR 2.98, p = 0.006) were independent factors associated with complicated AA.Conclusions. Peripheral blood eosinophils appear to serve as a valuable biomarker for identifying cases of complicated AA among the adult population but not among children. Prospective studies will help elucidate this phenomenon.