What are the characteristics of RLQ pain?

Characteristics of Right Lower Quadrant (RLQ) Pain

RLQ pain is most commonly caused by appendicitis, but can also be attributed to right colonic diverticulitis (8% of cases), intestinal obstruction (3% of cases), and numerous other conditions affecting the bowel, reproductive, and urinary systems. 1

Common Causes of RLQ Pain

Appendicitis (Most Common Surgical Cause)

• Typical presentation includes:
  • Periumbilical pain migrating to RLQ
  • Fever (significant difference compared to non-appendicitis causes, p=0.004) 2
  • Nausea/vomiting
  • Loss of appetite
  • Rebound tenderness (significant difference compared to non-appendicitis causes, p=0.019) 2
  • Leukocytosis (occurs in approximately 50% of cases) 1
  • Elevated white cell count (p<0.001) 2
  • Increased neutrophil percentage (p<0.001) 2
  • Elevated C-reactive protein levels (p<0.001) 2

Other Common Causes

• Right colonic diverticulitis (8% of cases) 3, 1
• Intestinal obstruction (3% of cases) 3, 1
• Infectious enterocolitis (typhlitis, inflammatory terminal ileitis) 3
• Ureteral stones 3
• Gynecological conditions:
  • Benign adnexal masses
  • Pelvic inflammatory disease
  • Ovarian cysts
  • Pelvic congestion syndrome 3
• Gastrointestinal conditions:
  • Gastroenteritis
  • Colitis
  • Constipation
  • Inflammatory bowel disease 3

Diagnostic Approach

Imaging Findings

• CT abdomen and pelvis is the recommended first-line imaging modality for evaluating RLQ pain 3, 1

  • Provides high diagnostic yield for appendicitis (sensitivity 95%, specificity 94%)
  • Excellent for identifying alternative diagnoses (94.3% concordance with clinical diagnosis) 3
  • Should include both abdomen and pelvis, as limiting to just the pelvis would decrease sensitivity from 99% to 88% 4

• Ultrasound findings in appendicitis:

  • Non-compressible appendix
  • Diameter >6 mm
  • Wall thickening
  • Periappendiceal fluid 1

• MRI can be used particularly in pregnant patients and pediatric populations:

  • Can provide alternative diagnoses in up to 52% of cases
  • Alternatives identified include diverticulitis, ileitis, colitis, ischemia, small bowel adhesions, and more 3

Special Considerations

• Atypical presentations are common in:

  • Children under 5 years old
  • Elderly patients (may present with more signs of peritonitis, abdominal distension) 1
  • Immunocompromised patients 1

• Delayed diagnosis increases risk of perforation (occurs in 17-32% of appendicitis cases) 1

• Clinical observation is appropriate for patients without classical features of appendicitis or peritonitis, with repeated physical examinations to monitor for changes 2

Diagnostic Pitfalls to Avoid

• Relying solely on clinical signs and symptoms can lead to delayed diagnosis, especially in patients with atypical presentations 1
• Focusing imaging only on the pelvis may miss pathology in the abdomen that could be causing RLQ pain 4
• Failing to consider gynecological causes in female patients 3, 5
• Not recognizing that appendicitis is absent in approximately 50% of patients presenting with RLQ pain 3

By systematically evaluating the characteristics of RLQ pain and utilizing appropriate imaging, clinicians can accurately diagnose the underlying cause and implement appropriate management strategies to improve patient outcomes.