Appendicitis is the most common childhood surgical emergency, but the diagnosis can be challenging, especially in children, often leading to either unnecessary surgery in children without appendicitis, or a ruptured appendix and serious complications when the condition is missed. Now, emergency medicine physicians and scientists at the Proteomics Center at Children's Hospital Boston demonstrate that a protein detectable in urine might serve as a "biomarker" for appendicitis. Their report was published online June 23 by the Annals of Emergency Medicine.