What is the most appropriate management for a 27-year-old obese woman presenting 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

Ultrasound (US) should be the first-line diagnostic imaging modality for this 27-year-old obese woman presenting with right iliac fossa pain, anorexia, nausea, vomiting, tenderness, and leucocytosis. 1

Initial Diagnostic Approach

• Point-of-care Ultrasound (POCUS) is recommended as the most appropriate first-line diagnostic tool in adults with suspected appendicitis when imaging is indicated based on clinical assessment 1
• US has satisfactory sensitivity and specificity in diagnosing acute appendicitis, allowing for swift decision-making 1
• In obese patients, diagnostic performance of US may be limited, with higher false diagnosis rates compared to non-obese patients (46.2% vs 38.5% in females) 1

Diagnostic Algorithm

1. First step: Ultrasound evaluation

   • Graded compression technique should be used to displace intervening organs and simulate clinical deep abdominal palpation 1
   • Appendix visualization is key to diagnostic accuracy, but may be limited in obese patients 1

2. If US is inconclusive or negative:

   • Proceed to contrast-enhanced low-dose CT scan 1
   • Low-dose CT provides diagnostic accuracy not inferior to standard CT while reducing radiation exposure 1
   • CT has high sensitivity (85.7-100%) and specificity (94.8-100%) for diagnosing appendicitis 1

3. If imaging remains inconclusive but clinical suspicion is high:

   • Diagnostic laparoscopy is recommended to establish/exclude the diagnosis of acute appendicitis or alternative diagnoses 1
   • This is particularly important in patients with progressive or persistent pain despite negative imaging 1

Important Considerations

• Obesity is a significant limiting factor for US accuracy, with higher false diagnosis rates in obese patients 1
• The presence of anorexia, tachycardia, and rebound tenderness significantly predicts appendicitis 2
• C-reactive protein combined with leukocyte count has high predictive value for appendicitis (positive and negative predictive values of 93.2% and 92.3%, respectively) 3
• Diagnostic laparoscopy has both diagnostic and therapeutic value, allowing for immediate intervention if appendicitis is confirmed 1, 4

Pitfalls to Avoid

• Relying solely on clinical assessment without imaging in obese patients can lead to higher negative appendectomy rates 4
• Delaying diagnosis and treatment increases risk of perforation, which is associated with longer duration of pre-hospital symptoms (median 50h for perforated vs 17h for simple appendicitis) 2
• Overlooking alternative diagnoses, as the majority of patients with right iliac fossa pain do not have appendicitis 2
• Failing to consider gynecological causes, which account for approximately 22% of RIF pain cases in women 2

Based on the clinical presentation of right iliac fossa pain with anorexia, nausea, vomiting, tenderness, and leucocytosis in an obese 27-year-old woman, ultrasound should be the initial diagnostic approach, followed by CT if inconclusive, and diagnostic laparoscopy if clinical suspicion remains high despite negative imaging.