Predictors of Histopathology-proven Appendicitis in Acute Abdominal Pain: A Retrospective Observational Cross-sectional Study

Abstract Background: Acute appendicitis (AA) is a common surgical emergency that typically presents in the emergency department (ED) with abdominal pain, nausea, and right iliac fossa (RIF) tenderness – symptoms that often overlap with other conditions. This study aimed to identify clinical, laboratory, and radiological predictors of histopathology-confirmed AA patients. Methods: A retrospective review of ED patients with suspected AA (2018–2022) was conducted to analyze demographic, clinical, laboratory, and imaging predictors. Results: A total of 340 patients were included, with a mean age of 19.25 (standard deviation: 11.46) years; 212 (62.4%) were males. The most frequent symptoms were RIF pain (68.5%), migration of pain (52.6%), nausea/vomiting (75.0%), and anorexia (36.5%, P < 0.001). Physical examination revealed RIF tenderness in 92.6% ( P = 0.039), rebound tenderness in 72.9% ( P < 0.001), and a positive psoas sign in 6.8% ( P < 0.001). Laboratory tests showed leukocytosis (white blood cell >11,000) in 56.5% ( P = 0.045) and C-reactive protein >6 mg/L in 70.9% ( P = 0.045). Imaging confirmed AA in 27.4% of ultrasound and 17.4% of computed tomography scans ( P = 0.042 and P = 0.005, respectively). An Alvarado score ≥3 was also strongly associated with histopathologically confirmed AA (adjusted odds ratio 5.06 × 10 7 ; 95% confidence interval: 2.51 × 10 -8 –1.02 × 10 -5 P < 0.001), along with the above clinical, laboratory, and imaging parameters. Conclusion: RIF pain, pain migration, nausea/vomiting, anorexia, and abdominal tenderness, along with elevated inflammatory markers and positive imaging, serve as significant predictors of AA. The Alvarado score remains a useful composite tool to support diagnosis in the ED setting.