A diagnostic mismatch was observed in nine cases: in three cases, salivary CRP outperformed serum CRP by correctly identifying appendicitis when serum yielded a false negative; in two cases, serum CRP outperformed saliva by correctly identifying appendicitis when saliva yielded a false negative; in two cases, serum CRP produced false positives for appendicitis that saliva did not; and in two cases, saliva CRP produced false positives that serum did not. Here, CRP is linked to appendicitis.