The Association Between C-Reactive Protein Levels and Pediatric Appendicitis Score and the Severity of Appendicitis in Children.

BACKGROUND: Acute appendicitis is a common cause of abdominal pain leading to emergent abdominal surgery in children. C-reactive protein (CRP), an inflammatory marker typically elevated in acute appendicitis, and Pediatric Appendicitis Score (PAS), a clinical scoring system used for the diagnosis of appendicitis, have the potential to predict the severity of inflammation of the appendix. This may be useful in helping the physician make a treatment plan prior to surgery.

OBJECTIVE: The purpose of this study was to assess whether CRP value and PAS differ with the extent of inflammation of the appendix seen on histologic examination.

METHODS: This was a prospective observational study of patients diagnosed with acute appendicitis via computed tomography or ultrasound. Enrolled patients had CRP levels drawn, PAS calculated, and appendix pathology reviewed. Appendix pathology was categorized by the pathologist on the basis of the level of inflammation: simple, suppurative, gangrenous, and perforated.

RESULTS: One hundred sixty-three patients were enrolled. CRP levels and PAS were statistically different (p < 0.002) among the four pathology classifications. Patients with simple appendicitis (n = 3) had a mean CRP of 2.95 mg/L and PAS of 3.9, patients with suppurative appendicitis (n = 99) had a mean CRP of 26.89 mg/L and PAS of 6.5, patients with gangrenous appendicitis (n = 56) had a mean CRP of 91.11 mg/L and PAS of 7.5, and patients with perforated appendicitis (n = 6) had a mean CRP of 154.17 mg/L and PAS of 7. The results remained statistically significant (p < 0.002) after adjusting for age, race, and sex. When combined-PAS ≥ 8 and CRP level > 40 mg/L-the specificity of complicated appendicitis was 91.2% and positive predictive value was 72.7%.

CONCLUSIONS: Higher CRP levels and PAS were associated with increased histologic inflammation of the appendix. This study provides preliminary evidence that CRP and PAS could potentially assist in treatment decisions for appendicitis.