Time course response of inflammatory markers in pediatric appendicitis

We aim to evaluate the diagnostic value and time course response of the triple inflammatory markers: white blood cell count (WBC), neutrophil percentage (Neu), and C-reactive protein (CRP) in pediatric acute appendicitis.

A retrospective review of clinical data pertaining to 1391 patients admitted with suspicion for pediatric appendicitis from 2012 to 2017 was conducted. Triple inflammatory markers were acquired upon admission. Appendicitis was confirmed histologically post-appendectomy. The diagnostic value and time course response of these markers was trended in relation to the duration of abdominal pain on admission.

718 patients had histologically confirmed appendicitis. WBC and Neu demonstrate high sensitivity for early appendicitis at 94.6% and 80.0% at Day 1, while CRP demonstrates highest sensitivity of 97.9% at Day 4. The triple markers had poor overall diagnostic value when interpreted individually, however, had a high combined sensitivity of 99.7% and negative predictive value of 98.7% regardless of duration of disease. Overall negative appendectomy rate was 6.7% (n = 52). Among 19 patients with triple markers negative who underwent appendectomy, 17 (89.5%) were histologically normal.

The triple inflammatory markers have limited diagnostic value when interpreted individually, but are strong discriminators of pediatric appendicitis when combined. Their high sensitivity and negative predictive value could potentially help patients avoid unnecessary admissions or costly imaging studies, and reduce negative appendectomy rates. In addition, their objective nature confers an advantage over existing clinical scoring systems which comprise subjective elements.