What is the most appropriate management for a 27-year-old obese woman with right iliac fossa pain, anorexia, nausea, vomiting, moderate right iliac fossa tenderness, and leucocytosis (elevated white blood cell count)?

Management of Right Iliac Fossa Pain in a 27-Year-Old Obese Woman

CT scan of the abdomen and pelvis is the most appropriate initial management for this patient with suspected appendicitis. 1, 2

Clinical Presentation Analysis

The patient's presentation strongly suggests acute appendicitis:

• 27-year-old obese woman
• Right iliac fossa pain
• Associated anorexia, nausea, and vomiting
• Moderate right iliac fossa tenderness on examination
• Leukocytosis

This constellation of symptoms represents the "classic" clinical presentation of appendicitis, which includes periumbilical pain migrating to the right lower quadrant, loss of appetite, nausea/vomiting, and leukocytosis (present in about 50% of patients with appendicitis) 1.

Diagnostic Approach

Why CT is the Optimal Choice (Option B)

1. Superior Diagnostic Performance:

   • CT has become the primary diagnostic imaging modality for suspected appendicitis due to its high diagnostic yield 1
   • Sensitivity ranges from 85.7% to 100% and specificity from 94.8% to 100% 1
   • Contrast-enhanced CT without enteral contrast has sensitivity of 90-100% and specificity of 94.8-100% 1

2. Obesity Consideration:

   • The patient is obese, which significantly limits the utility of ultrasound
   • CT performs better in obese patients, with one study showing 100% sensitivity and 99.5% specificity in patients with BMI >25 1

3. Reduction in Negative Appendectomy Rate (NAR):

   • Preoperative CT reduces the NAR to 1.7-7.7%, compared to historical rates of 14.7% 1
   • This prevents unnecessary surgical interventions and their associated morbidity

Why Other Options Are Less Appropriate

1. Ultrasound (Option C):

   • While ultrasound can be useful, it has significant limitations in obese patients
   • Appendix visualization is often limited in obese patients
   • In a study of pre-menopausal women with right iliac fossa pain, ultrasound identified only 5 of 26 cases of acute appendicitis that were later confirmed by laparoscopy 3

2. Diagnostic Laparoscopy (Option D):

   • Should not be the first-line approach without prior imaging
   • The American College of Radiology recommends imaging before surgical intervention to reduce unnecessary procedures 1, 2
   • Proceeding directly to laparoscopy without imaging increases the risk of negative appendectomy

3. Open Surgery (Option A):

   • Most inappropriate option as first-line management
   • Modern practice favors imaging-guided diagnosis followed by laparoscopic approach if surgery is needed
   • Open surgery without prior imaging confirmation carries significant risk of unnecessary intervention

Management Algorithm

1. Initial Imaging:

   • Perform CT abdomen and pelvis with IV contrast
   • No need for oral contrast in this setting (may delay diagnosis and potentially increase perforation risk) 1

2. If CT confirms appendicitis:

   • Surgical consultation
   • Preoperative management: NPO status, IV fluid resuscitation, and broad-spectrum antibiotics 2
   • Laparoscopic appendectomy (preferred over open approach) 2

3. If CT identifies alternative diagnosis:

   • Manage according to specific findings
   • CT can identify other causes of right lower quadrant pain such as diverticulitis, gynecological conditions, or urinary tract disorders 2

Important Considerations

• Timing is critical: Delayed diagnosis increases risk of perforation (occurs in 17-32% of appendicitis cases) 2
• Diagnostic pitfall: Relying solely on clinical signs without imaging can lead to missed diagnoses, especially in patients with atypical presentations 2
• Radiation concern: While CT involves radiation exposure, the benefit of accurate diagnosis outweighs the risk in this clinical scenario with high pretest probability of appendicitis

In summary, CT abdomen and pelvis is the most appropriate initial management for this patient, offering the highest diagnostic accuracy while guiding appropriate treatment decisions and minimizing unnecessary surgical interventions.