History, exam, and labs: Is one enough to diagnose acute adult appendicitis?

No, none of the 3--history, exam, or labs-- is sufficiently accurate to diagnose acute appendicitis (strength of recommendation [SOR]: A, based on meta-analysis of high- quality studies). When combined, the following tests are helpful: an elevated C-reactive protein (CRP), elevated total white blood cell (WBC) count, elevated percentage of polymorphonuclear leukocyte (PMN) cells (left shift), and the presence of guarding or rebound on physical examination. The combination of any 2 of these tests yields a very high positive likelihood ratio (LR +), but the absence of these does not exclude appendicitis (SOR: A, based on meta-analysis of high-quality studies)