What is the appropriate diagnosis and treatment for an elderly female patient with abdominal pain on the lower right side?

Diagnosis and Management of Right Lower Quadrant Abdominal Pain in Elderly Females

Do not rely on clinical examination and laboratory tests alone to diagnose the cause of right lower quadrant pain in elderly patients—obtain CT imaging with IV contrast immediately, as this is the diagnostic standard that changes diagnosis in 51% of cases and prevents life-threatening delays. 1

Critical First Step: Rule Out Life-Threatening Conditions

Mesenteric ischemia must be excluded urgently in elderly patients presenting with abdominal pain, particularly when pain severity is disproportionate to physical examination findings, as mortality ranges from 30-90%. 2 Elderly patients are at highest risk due to atherosclerotic disease, and presentation is typically atypical with nonspecific findings. 2 Laboratory values including metabolic acidosis, elevated lactate, and elevated D-dimer are insufficient for diagnosis—imaging is essential. 2

Primary Differential Diagnoses for Right Lower Quadrant Pain

Appendicitis

• Clinical signs and symptoms alone cannot reliably diagnose or exclude appendicitis in elderly patients. 1
• The typical triad of migrating right lower quadrant pain, fever, and leukocytosis is infrequently observed in elderly patients. 1
• Many elderly patients present with signs of ileus or bowel obstruction rather than classic appendicitis symptoms. 1
• Right lower quadrant tenderness, nausea, and vomiting are common, but fever is present in only 30-80% of cases. 1
• Elderly patients often present with more advanced disease showing signs of peritonitis (abdominal distension, generalized tenderness and guarding, rebound tenderness, palpable mass). 1
• Elevated leukocyte count and CRP cannot establish the diagnosis, but normal values have 100% negative predictive value for excluding appendicitis. 1

Right-Sided Diverticulitis

• Right-sided diverticulitis is a rare but important mimic of appendicitis in Western populations, though more common in Asian patients. 3
• This condition presents identically to appendicitis with right lower quadrant pain, fever, nausea, and laboratory abnormalities. 3
• CT imaging is essential to distinguish right-sided diverticulitis from appendicitis and avoid unnecessary surgery. 3

Other Gastrointestinal Causes

• Inflammatory and infectious conditions involving the ileocecal region, epiploic appendagitis, omental and mesenteric pathology, and malignancies can all present with right lower quadrant pain. 4
• Epiploic appendagitis is self-limiting and can mimic appendicitis or diverticulitis; correct CT diagnosis prevents unnecessary hospitalization, antibiotics, or surgery. 5

Atypical Presentations

• Acute cholecystitis can present with atypical pain patterns in elderly patients—only 43.3% have positive Murphy's sign, 12% have atypical pain location, and 5% have no pain at all. 2
• Pneumonia can present as abdominal pain in elderly patients and should be considered. 2

Diagnostic Approach

Imaging Strategy

CT abdomen and pelvis with IV contrast is the initial imaging study of choice, with 98-99% sensitivity and 99-100% specificity for evaluating abdominal pain in elderly patients. 1, 2 This imaging modality:

• Changes the leading diagnosis in 51% of patients 1, 2
• Changes admission decisions in 25% of patients 1, 2
• Is especially critical in elderly patients where laboratory tests are nonspecific and may be normal despite serious infection 1, 2

For patients who cannot receive IV contrast (severe renal disease or contrast allergy), use ultrasound, MRI, or CT without contrast as alternative approaches. 1

Plain radiography has extremely limited value—it demonstrates low sensitivity for sources of abdominal pain and fever, and 25% of patients with mesenteric ischemia have normal radiographs. 1, 2

Clinical Examination Limitations

• Clinical examination alone results in misdiagnosis rates of 34-68% in elderly patients without imaging. 2
• Physical examination can be misleadingly benign even with catastrophic conditions like mesenteric ischemia. 2
• Pre-existing medical disorders and polypharmacy further complicate clinical diagnosis. 2

Laboratory Testing

• Laboratory tests alone have insufficient diagnostic accuracy for acute abdominal conditions in elderly patients. 1
• While two or more elevated inflammatory markers increase likelihood of appendicitis in general populations, this is unreliable in elderly patients. 1
• Scoring systems like the Alvarado score may help exclude appendicitis (with scores <5) but should not be used alone to diagnose it. 1

Common Pitfalls to Avoid

• Do not delay imaging while waiting for "classic" symptoms to develop—elderly patients frequently present with atypical symptoms and delayed presentations. 1, 2
• Do not assume normal vital signs or laboratory values exclude serious pathology—fever is absent in many elderly patients with serious infections. 1, 2
• Do not rely on scoring systems alone—they are suggested only for excluding disease, not confirming it, in elderly populations. 1
• Do not overlook gynecological causes in elderly females—consider ovarian pathology, though less common in this age group. 6

Treatment Considerations

Once imaging confirms the diagnosis:

• Appendicitis requires hospital admission and typically surgical intervention. 7
• Right-sided diverticulitis is managed medically with IV antibiotics and bowel rest, typically resolving in 3 days. 3
• Epiploic appendagitis is self-limiting and requires only conservative management. 5
• Mesenteric ischemia requires urgent surgical consultation given the extremely high mortality rate. 2