What is the recommended diagnostic workup for an 18-year-old female with intermittent sharp right upper quadrant (RUQ) abdominal pain?

Diagnostic Workup for 18-year-old Female with Intermittent RUQ Abdominal Pain

Ultrasonography of the abdomen is the recommended first-line imaging study for an 18-year-old female presenting with intermittent right upper quadrant (RUQ) abdominal pain. 1, 2

Initial Diagnostic Approach

• Obtain a pregnancy test before any imaging studies for all females of reproductive age to rule out pregnancy-related conditions 2
• Order complete blood count (CBC) to assess for leukocytosis, which may indicate infection or inflammation 2
• Perform liver function tests (LFTs) including ALT, AST, alkaline phosphatase, GGT, and bilirubin to evaluate for hepatobiliary disease 2
• Check pancreatic enzymes (amylase and lipase) to rule out pancreatitis 2
• Order renal function tests (BUN, creatinine) to assess kidney function 2
• Conduct urinalysis to evaluate for renal stones or infection 1

Imaging Studies

• Ultrasonography of the abdomen is the first-line imaging modality with the highest appropriateness rating (9/9) according to the American College of Radiology (ACR) Appropriateness Criteria 1
• Ultrasonography has several advantages:
  • No radiation exposure 1
  • Readily available 1
  • Can identify gallbladder pathology, liver abnormalities, and other potential causes of RUQ pain 1, 2
  • Particularly valuable for evaluating gallbladder disease, which is a common cause of RUQ pain 1, 3

Second-Line Imaging Options

If ultrasonography is non-diagnostic and symptoms persist, consider:

• Cholescintigraphy (HIDA scan) - particularly if gallbladder disease is suspected based on ultrasound findings (appropriateness rating 6/9) 1
• CT of abdomen with contrast media (appropriateness rating 6/9) 1
• MRI of abdomen without and with contrast media (appropriateness rating 6/9) - especially useful when avoiding radiation exposure is important 1

Important Clinical Considerations

• Acute cholecystitis is the most common cause of acute RUQ pain, but more than one-third of patients with acute RUQ pain have other causes 3
• Consider non-biliary causes of RUQ pain in young females, including:
  • Irritable bowel syndrome (IBS) - a common but often overlooked cause of chronic RUQ pain 4
  • Hepatic masses or lesions - rare but important to exclude 5
  • Extra-abdominal causes such as respiratory infections 6

Common Pitfalls to Avoid

• Failing to obtain a pregnancy test before imaging studies in females of reproductive age 2
• Relying solely on laboratory tests without appropriate imaging when indicated 2
• Using CT as first-line imaging due to unnecessary radiation exposure in young patients 2
• Missing non-gallbladder causes of RUQ pain, as more than one-third of patients with RUQ pain do not have acute cholecystitis 3
• Overlooking functional causes such as irritable bowel syndrome, which may require specific testing like balloon distension of the intestine to reproduce pain 4