What is the best initial management for a patient with right lower quadrant pain and a mildly elevated WBC count without signs of an acute abdomen?

Management of Right Lower Quadrant Pain with Normal WBC

Obtain CT abdomen and pelvis with IV contrast immediately—normal WBC does not exclude appendicitis or other surgical pathology requiring urgent intervention. 1

Why Imaging is Mandatory Despite Normal WBC

• The "classic" presentation of appendicitis (fever, leukocytosis, peritoneal signs) occurs in only approximately 50% of patients, making clinical assessment alone unreliable 1
• Never rely on normal WBC alone to exclude appendicitis or other surgical pathology—imaging is mandatory 1
• CT identifies the cause of RLQ pain in the majority of cases, with 41% of patients with non-appendiceal diagnoses requiring hospitalization and 22% requiring surgical or image-guided intervention 1
• CT changes management in 43% of patients initially suspected to have appendicitis clinically 1

CT as First-Line Imaging

• CT abdomen and pelvis with IV contrast provides 95% sensitivity and 94% specificity for appendicitis, making it the imaging modality of choice 2, 1
• CT excels at detecting both appendicitis and the numerous alternative diagnoses that cause RLQ pain (gynecologic, gastrointestinal, genitourinary, vascular, musculoskeletal) 2, 1, 3, 4
• The American College of Radiology recommends CT abdomen and pelvis as the primary imaging modality for RLQ pain without leukocytosis 2, 1

Why Not Ultrasound First

• Ultrasound has significantly lower sensitivity (51.8%) and specificity (81.4%) compared to CT in the general population with RLQ pain 1
• Ultrasound should only be considered as the initial modality in reproductive-age females where gynecologic pathology is the primary concern 1

Management Algorithm

1. Order CT abdomen and pelvis with IV contrast immediately 2, 1
2. If CT shows appendicitis, proceed to surgical consultation regardless of WBC count 1
3. If CT excludes appendicitis, the most frequent alternative diagnoses include gynecologic conditions, gastrointestinal etiologies, genitourinary causes, vascular, and musculoskeletal causes 1
4. If CT is negative but focal peritoneal signs persist on serial abdominal exams (rebound tenderness, guarding localized to RLQ), obtain surgical consultation for possible exploratory laparoscopy 5

Critical Pitfalls to Avoid

• Do not discharge home with pain instructions based on normal WBC alone—this misses surgical pathology in a significant proportion of patients 1
• Do not admit for serial labs and observation without imaging first—this delays definitive diagnosis and appropriate intervention 1
• Asking about appendicitis history is irrelevant to acute management and wastes time 1
• Even with negative imaging, if focal peritoneal signs persist (rebound, guarding), surgical consultation is warranted as imaging can miss perforated cecal diverticula and other rare pathology 5