Characteristics of Right Lower Quadrant Pain
Right lower quadrant (RLQ) pain is characterized by periumbilical pain that migrates to the RLQ, often accompanied by fever, nausea/vomiting, loss of appetite, and leukocytosis in approximately 50% of cases when caused by appendicitis, which is the most common surgical cause of RLQ pain. 1, 2
Common Clinical Characteristics of RLQ Pain
Pain Characteristics
- Location: Right lower quadrant of abdomen (below umbilicus, right side)
- Migration pattern: Often begins periumbilically and migrates to RLQ (especially in appendicitis)
- Quality: May be sharp, dull, or cramping
- Severity: Can range from mild to severe
- Duration: Acute onset or gradual development depending on cause
Associated Symptoms
- Fever (significant differentiator between appendicitis and other causes) 3
- Nausea and/or vomiting
- Loss of appetite (anorexia)
- Rebound tenderness (pain when pressure is released - indicates peritoneal irritation)
- Diarrhea (may be present in some cases)
Laboratory Findings
- Leukocytosis (elevated white blood cell count)
- Elevated neutrophil percentage
- Increased C-reactive protein levels
These laboratory values show significant differences between appendicitis and other causes of RLQ pain 3.
Differential Diagnosis of RLQ Pain
Gastrointestinal Causes
- Acute appendicitis (most common surgical cause)
- Right colonic diverticulitis (8% of RLQ pain cases) 1
- Inflammatory bowel disease (terminal ileitis, Crohn's disease)
- Infectious enterocolitis (typhlitis)
- Intestinal obstruction (3% of RLQ pain cases) 1
- Mesenteric adenitis
Genitourinary Causes
- Ureteral stones
- Pyelonephritis
- Urinary tract infection
Gynecologic Causes (in females)
- Ovarian cysts or torsion
- Pelvic inflammatory disease
- Ectopic pregnancy
- Endometriosis
Other Causes
- Epiploic appendagitis
- Omental infarction
- Hernia (e.g., right paraduodenal hernia)
- Mesenteric lymphadenitis
Imaging Findings in RLQ Pain
CT Abdomen and Pelvis Findings
- Appendicitis: Appendiceal dilatation, wall thickening, periappendiceal fat stranding, appendicoliths 2
- Diverticulitis: Colonic wall thickening, pericolonic fat stranding
- Inflammatory bowel disease: Terminal ileal thickening, mesenteric hypervascularity
- Urolithiasis: Ureteral stones, hydronephrosis
Ultrasound Findings
- Appendicitis: Non-compressible appendix, diameter >6mm, wall thickening, periappendiceal fluid 2
- Gynecologic conditions: Ovarian cysts, tubo-ovarian abscess, ectopic pregnancy
Special Considerations
Atypical Presentations
- Children under 5 years and elderly patients may present with more generalized symptoms
- Immunocompromised patients (including those with HIV) may have atypical presentations 2
- Patients without classic symptoms may benefit from active observation and repeated examinations 3
Diagnostic Pitfalls
- Relying solely on clinical signs without imaging can lead to delayed diagnosis
- Delayed diagnosis increases risk of perforation (occurs in 17-32% of appendicitis cases) 2
- Over-reliance on a single diagnostic test rather than considering the entire clinical picture can lead to misdiagnosis 2
CT imaging has significantly reduced the negative appendectomy rate from as high as 25% to approximately 1-3%, highlighting the importance of appropriate imaging in evaluating RLQ pain 1, 2.