What could be causing sharp upper quadrant pain wrapping around to the side and felt under the rib cage in a middle-aged adult with a history of peptic ulcer disease or gallstones?

Sharp Upper Quadrant Pain Wrapping Around to the Side

Start with right upper quadrant ultrasound immediately—it is the first-line imaging test for this presentation and will guide all subsequent management decisions. 1, 2

Initial Diagnostic Approach

Your clinical presentation of sharp upper quadrant pain wrapping around to the side under the rib cage strongly suggests biliary disease, particularly acute cholecystitis or biliary colic, which are the most common causes of this pain pattern. 1, 3, 4

Why Ultrasound First

• Ultrasound is rated 9/9 (usually appropriate) by the American College of Radiology for right upper quadrant pain evaluation and serves as the definitive initial test. 1
• It detects gallstones with 96% accuracy, evaluates for gallbladder wall thickening, assesses for bile duct dilatation, and can identify alternative diagnoses. 1, 5
• The study is fast, portable, lacks radiation exposure, costs less than CT or MRI, and provides morphologic evaluation of multiple organ systems. 1, 2
• Over one-third of patients initially suspected to have acute cholecystitis actually have RUQ pain from other causes that ultrasound can identify. 4, 2

Key Clinical Features to Assess

• Look for Murphy's sign during the ultrasound examination (focal tenderness over the sonographically localized gallbladder), though be aware this has relatively low specificity and is unreliable if pain medication was given prior to imaging. 1
• Obtain liver function tests including GGT, alkaline phosphatase, AST/ALT, total and direct bilirubin, and complete blood count alongside imaging. 6
• Assess for fever, jaundice, and timing relative to meals—postprandial pain suggests biliary colic, while fever with persistent pain suggests acute cholecystitis. 1, 7

Algorithmic Next Steps Based on Ultrasound Results

If Ultrasound Shows Gallstones + Gallbladder Wall Thickening

• This confirms acute cholecystitis, and urgent surgical consultation for cholecystectomy is indicated for uncomplicated disease. 3, 2
• Consider CT with IV contrast only if complications are suspected (perforation, abscess, emphysematous cholecystitis) to guide surgical planning. 1

If Ultrasound Shows Gallstones + Dilated Common Bile Duct

• Proceed directly to MRCP, which has 85-100% sensitivity and 90% specificity for detecting choledocholithiasis and biliary obstruction. 5, 6
• MRCP is superior to CT for assessing suspected biliary sources of RUQ pain and provides comprehensive visualization of the entire hepatobiliary system. 5, 8
• MRCP identifies the level and cause of biliary obstruction with 91-100% accuracy, including stones, strictures, and masses. 5

If Ultrasound is Negative or Equivocal

• Order MRCP as the next diagnostic step to comprehensively evaluate the biliary tree for stones, strictures, or obstruction that ultrasound may have missed. 5, 8, 6
• Consider cholecystokinin-augmented cholescintigraphy (HIDA scan) if MRCP is negative and you suspect chronic gallbladder disease, biliary dyskinesia, or acalculous cholecystitis. 5, 6
• A low gallbladder ejection fraction (<35%) on HIDA scan supports the diagnosis of biliary dyskinesia in patients with typical biliary-type pain. 6

If Both Ultrasound and MRCP are Negative

• Consider CT abdomen/pelvis with IV contrast to evaluate for alternative diagnoses including hepatic pathology, pancreatic inflammation, renal disease, or musculoskeletal causes. 8, 6, 4
• Peptic ulcer disease typically presents with epigastric pain rather than RUQ pain, though it can occasionally radiate to the right upper quadrant. 7

Important Clinical Caveats

• Do not order CT as initial imaging for chronic RUQ pain—CT has only ~75% sensitivity for gallstones, exposes patients to unnecessary radiation, and is inferior to ultrasound for gallbladder pathology. 6, 3
• Do not order HIDA scan as the primary test unless acute cholecystitis is the primary clinical concern after negative or equivocal ultrasound. 5
• Elevated liver function tests indicate biliary obstruction or cholestasis, which requires anatomic visualization of the bile ducts—something MRCP provides but HIDA scan does not. 5
• Consider slipping rib syndrome if the patient has a history of previous trauma or thoracic surgery, particularly if pain is associated with a palpable protrusion. 9
• Cholescintigraphy has slightly higher sensitivity (97%) and specificity (90%) than ultrasound for acute cholecystitis, but ultrasound remains preferred initially for the reasons outlined above. 1, 2