Diagnostic value of WBC count and C-reactive protein for detection of acute appendicitis in children

Background: The role of inflammatory markers in diagnosis of acute appendicitis has not been clearly defined. Objectives: To determine the diagnostic value of WBC count and C-reactive protein in diagnosis or rejection of acute appendicitis in children. Methods: In a prospective study, 100 child with probable diagnosis of acute appendicitis (Alvarado score ≤5) referred to Tabriz Pediatric Hospital during 14 months from April 2007 to May 2008 were studied. Serum CRP, WBC count, and neutrophil percentage were compared in patients with and without definite diagnosis of acute appendicitis. Findings: Out of 100 patients, 54 were males and 46 females with a mean age of 9.6±2.7 years. The number of patients with definite diagnosis of acute appendicitis was 48. Children with final diagnosis of acute appendicitis had significantly higher value of inflammatory markers. Elevated CRP showed the greatest sensitivity (85%) and negative predictive value (83%). None of the children with normal markers had acute appendicitis. Conclusion: This study showed that despite elevation of these inflammatory markers in patients with acute appendicitis, it is unwise to completely rely on results of such tests in confirming or rejecting the disease. Normal values obtained for all three markers are unlikely to be associated with pathologically confirmed appendicitis in children.