Misdiagnosed acute appendicitis in children in the emergency department

Background: To identify clinical features that distinguish children with appendicitis who visited the emergency department twice or more from those diagnosed on the first visit to the emergency department. Methods: A retrospective review of all children with appendicitis diagnosed in the emergency department between January and December 2004 was conducted. Records were reviewed for all patients on their initial presentation to the emergency department. Clinical features were compared between those children who were misdiagnosed and those who were diagnosed correctly. Results: One hundred seventy-three cases were included (mean age, 10.4 years). Twenty-six (15%) were seen twice or more in the emergency department before appendicitis was diagnosed. Misdiagnosed patients had a relatively shorter duration of symptoms at their initial visit, and most presented late at night. Eighteen misdiagnosed patients (69.2%) initially visited the emergency department within 24 hours of onset of symptoms. Compared with patients diagnosed correctly on initial presentation, misdiagnosed patients had a significantly shorter hospital stay, fewer laboratory tests, and fewer physical findings of right lower quadrant tenderness, muscle guarding, rebound tenderness, fever, and migrating pain. Patients diagnosed late at night had a significantly shorter hospital stay and fewer abdominal ultrasound evaluations. On final presentation, initially misdiagnosed patients had a higher rate of appendiceal perforation than did correctly diagnosed patients. Conclusion: Misdiagnosed appendicitis is a problem in the emergency department. A shorter stay in the emergency department, fewer laboratory tests, less diagnostic imaging, and fewer physical findings may be responsible for misdiagnosed appendicitis late at night in the emergency department.