Can common serum biomarkers predict complicated appendicitis in children?

Purpose: As appendicitis in children can be managed differently according to the severity of the disease, we investigated whether commonly used serum biomarkers on admission could distinguish between simple and complicated appendicitis. Methods: Admission white blood cell (WBC), neutrophil (NEU), and C-reactive protein (CRP) levels were analysed by ROC curve, and Kruskal–Wallis and contingency tests. Patients were divided according to age and histology [normal appendix (NA), simple appendicitis (SA), complicated appendicitis (CA)]. Results: Of 1197 children (NA = 186, SA = 685, CA = 326), 7% were <5 years, 55% 5–12, 38% 13–17. CA patients had higher CRP and WBC levels than NA and SA (p < 0.0001). NEU levels were lower in NA compared to SA or CA (p < 0.0001), but were similar between SA and CA (p = 0.6). CA patients had higher CRP and WBC levels than SA patients in 5–12- (p < 0.0001) and 13–17-year groups (p = 0.0075, p = 0.005), but not in <5-year group (p = 0.72, p = 0.81). We found CRP >40 mg/L in 58% CA and 37% SA (p < 0.0001), and WBC >15 × 10⁹/L in 58% CA and 43% SA (p < 0.0001). Conclusions: Admission CRP and WBC levels may help the clinician predict complicated appendicitis in children older than 5 years of age. Early distinction of appendicitis severity using these tests may guide caregivers in the preoperative decision-making process.