In a 21‑year‑old woman presenting to the emergency department with right lower‑quadrant abdominal pain, anorexia, rebound tenderness, and leukocytosis, what is the most appropriate next step in management?

CT Abdomen and Pelvis with IV Contrast is the Most Appropriate Next Step

In this 21-year-old woman with classic appendicitis presentation (RLQ pain, anorexia, rebound tenderness, and leukocytosis), CT abdomen and pelvis with IV contrast should be performed before proceeding to surgery. 1

Why Imaging Before Surgery is Essential

Even with a classic clinical presentation, preoperative imaging is critical because:

• Clinical diagnosis alone has unacceptably high negative appendectomy rates of 14.7-25% without preoperative imaging, which drops dramatically to 1.7-7.7% when CT is performed first 2, 3
• The classic presentation occurs in only approximately 50% of appendicitis cases, making clinical assessment unreliable 3, 4
• CT identifies alternative diagnoses in 23-45% of patients presenting with RLQ pain and classic symptoms, fundamentally changing management 2, 3, 5

Diagnostic Performance of CT

CT abdomen and pelvis with IV contrast demonstrates:

• Sensitivity: 85.7-100% 1, 2
• Specificity: 94.8-100% 1, 2
• Superior to non-contrast CT, with significantly better sensitivity (100% vs 90.5%) and easier appendix identification 6, 7

Why Not Proceed Directly to Open Appendectomy

Immediate surgery without imaging risks:

• Unnecessary surgery in up to 25% of patients when relying on clinical assessment alone 3, 4
• Missing alternative surgical conditions such as right-sided diverticulitis (8% of cases), ovarian pathology (21.6% of alternative diagnoses), or intestinal obstruction (3% of cases) 3, 5
• Inability to assess for perforation or abscess formation, which may change surgical approach 3

Why Not Discharge

Discharge is inappropriate because:

• This patient has high-risk features: rebound tenderness (indicating peritoneal irritation), leukocytosis, and anorexia are all strongly associated with appendicitis 3, 4
• Rebound tenderness is a key sign of established appendicitis requiring definitive evaluation 3, 4
• The combination of fever, elevated WBC, and rebound tenderness creates only a 1% missed appendicitis rate, but this patient still requires imaging confirmation 3

Recommended Imaging Protocol

Order CT abdomen and pelvis with IV contrast without oral contrast for: 1, 3

• Rapid acquisition without delays from oral contrast administration
• Excellent sensitivity and specificity (90-100% and 94.8-100% respectively)
• Detection of alternative diagnoses
• Assessment for perforation and abscess formation

Critical Diagnostic Criteria on CT

Look for: 3

• Maximal outer diameter >8.2 mm (highly suggestive of appendicitis)
• Periappendiceal fat stranding
• Absence of intraluminal gas
• Presence of appendicoliths

Next Steps After CT

• If appendicitis confirmed: Proceed to surgical consultation and appendectomy 3
• If alternative diagnosis identified: Manage accordingly 3, 5
• If negative CT: Consider safe discharge with 24-hour follow-up 3