Management of Right Lower Quadrant Pain Without Leukocytosis

Initial Diagnostic Approach

The American College of Radiology recommends CT abdomen and pelvis with IV contrast as the imaging modality of choice for evaluating RLQ pain without leukocytosis, providing superior diagnostic accuracy (95% sensitivity, 94% specificity) for appendicitis, 1, 2
CT abdomen and pelvis remains the primary imaging modality even in the absence of leukocytosis, as the "classic" presentation of appendicitis occurs in only approximately 50% of patients, 3, 4
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, 2

The American College of Radiology notes that when CT excludes appendicitis in patients with RLQ pain and normal WBC, the most frequent diagnoses include gynecologic conditions, gastrointestinal etiologies, genitourinary causes, vascular, and musculoskeletal causes, 1, 2

Ultrasound has significantly lower sensitivity (51.8%) and specificity (81.4%) compared to CT in the general population with RLQ pain, 7, 5
The American College of Radiology suggests considering ultrasound as the initial modality only in reproductive-age females where gynecologic pathology is the primary concern, 1, 2

MRI with diffusion-weighted imaging (DWI) achieves specificity and positive predictive value of 100% with sensitivity 97-99% for appendicitis, and should be reserved for pregnant patients or when radiation exposure is contraindicated, 2

The American College of Radiology recommends obtaining CT abdomen and pelvis with IV contrast as the first-line imaging for RLQ pain without leukocytosis, 1, 2
If CT shows appendicitis, proceed to surgical consultation regardless of WBC count, 3, 4

Never rely on normal WBC alone to exclude appendicitis or other surgical pathology—imaging is mandatory, 3, 4
CT changes management in 43% of patients initially suspected to have appendicitis clinically, 1