What is the appropriate management for a patient with severe slicing pain in the lower right quadrant of the abdomen, negative McBurney (appendicitis test) sign, negative gynecology test, and no radiation of pain to the lower back?

Management of Right Lower Quadrant Pain with Negative McBurney Sign

Obtain CT abdomen and pelvis with IV contrast immediately as the first-line diagnostic study, as this achieves 95% sensitivity and 94% specificity for appendicitis while identifying alternative diagnoses in 94.3% of cases. 1

Why CT is Essential Despite Negative Clinical Findings

The absence of McBurney sign does not exclude appendicitis—this is a critical pitfall that leads to delayed diagnosis and increased perforation rates. 1

• Classic symptoms (fever, leukocytosis, typical tenderness) are present in only 50% of appendicitis cases, making clinical examination alone unreliable 1
• Clinical determination of appendicitis has negative appendectomy rates as high as 25% when relying on examination alone 2
• Normal laboratory values and absence of fever do not exclude serious pathology, particularly in early appendicitis 1

Imaging Protocol

CT abdomen and pelvis with IV contrast without oral contrast is the optimal study to avoid delays while maintaining diagnostic accuracy (sensitivity 90-100%, specificity 94.8-100%). 1

Why Not Ultrasound First?

While ultrasound can be considered in specific populations, it has significant limitations in this scenario:

• The appendix is not visualized in 20-81% of cases, creating diagnostic uncertainty 3
• Sensitivity ranges widely from 21% to 95.7% depending on operator experience and patient body habitus 3
• Equivocal ultrasound results require CT anyway, resulting in diagnostic delay without avoiding radiation 3
• CT identifies alternative diagnoses in 23-45% of cases presenting with suspected appendicitis, including right-sided colonic diverticulitis, bowel obstruction, colorectal malignancy, and mesenteric pathology 3

Broad Differential Diagnosis Beyond Appendicitis

The "slicing" pain quality and right lower quadrant location warrant consideration of multiple etiologies that CT can differentiate:

• Right colonic diverticulitis can precisely mimic appendicitis and is readily identified by CT 1
• Bowel obstruction, particularly if there is prior abdominal surgery history 3
• Colorectal malignancy, especially with history of rectal bleeding or unexplained weight loss 3
• Chronic appendicitis presents with atypical symptoms and milder tenderness, often diagnosed late due to lack of well-developed diagnostic criteria 4
• Ileocecal inflammatory conditions, epiploic appendagitis, omental pathology, and mesenteric conditions 5

Management Algorithm Based on CT Results

If CT Shows Acute Surgical Pathology (Appendicitis, Diverticulitis, Obstruction):

• Immediate surgical consultation 1
• NPO status, IV fluid resuscitation 3
• Broad-spectrum antibiotics 3
• 41% of patients with RLQ pain require hospitalization and 22% need surgical or image-guided intervention 1

If CT Shows Only Constipation or No Acute Findings:

• Initiate bowel regimen with stool softeners and/or osmotic laxatives 1
• Symptomatic pain relief with analgesics 1
• Reassessment within 24-48 hours 1

If CT is Negative but Symptoms Persist:

• Consider chronic appendicitis, which requires histopathologic confirmation after appendectomy 4
• Persistent pain failing to improve after 24-48 hours of conservative management warrants consideration of alternative diagnoses or delayed presentation 1

Critical Red Flags Requiring Reimaging

Do not assume initial negative imaging excludes pathology if clinical deterioration occurs:

• Fever development 1
• Persistent vomiting 1
• Worsening or peritoneal pain 1
• Inability to tolerate oral intake 1
• Development of local peritonitis during observation period 6

Common Pitfalls to Avoid

• Never discharge based solely on negative McBurney sign and normal labs—this risks missing early appendicitis or other serious pathology 2, 1
• Atypical presentations are common, including appendicitis with left lower quadrant pain due to long appendix projecting across midline or situs inversus 6
• Avoid relying on clinical scoring systems alone (like Alvarado score), as they have not improved diagnostic accuracy sufficiently 2
• Do not delay imaging in favor of prolonged observation when clinical suspicion exists, as this increases perforation risk 6