Differential Diagnosis for RUQ Pain

The differential diagnosis for right upper quadrant (RUQ) pain can be categorized into several groups based on the likelihood and potential severity of the conditions.

• Single Most Likely Diagnosis

  • Gallbladder Disease (Cholecystitis or Cholelithiasis): This is often the most common cause of RUQ pain, especially in females over 40 years old. The pain is typically constant, severe, and may radiate to the right shoulder or back. It is often associated with nausea, vomiting, and fever.

• Other Likely Diagnoses

  • Peptic Ulcer Disease: Both gastric and duodenal ulcers can cause RUQ pain, which may be exacerbated by food intake and relieved by antacids.
  • Hepatitis: Inflammation of the liver can cause RUQ pain, jaundice, and elevated liver enzymes. Viral hepatitis, drug-induced hepatitis, and alcoholic hepatitis are common causes.
  • Pyelonephritis or Kidney Stones: While these conditions primarily affect the flank, they can sometimes radiate pain to the RUQ, especially if the right kidney is involved.

• Do Not Miss Diagnoses

  • Appendicitis (with an atypical presentation): Although appendicitis typically presents with lower right quadrant pain, an inflamed appendix can sometimes be located in the RUQ, leading to atypical presentations.
  • Myocardial Infarction: Cardiac conditions, especially those involving the right coronary artery, can cause referred pain to the RUQ.
  • Pulmonary Embolism: A large pulmonary embolism can cause pleuritic chest pain that may be referred to the RUQ.
  • Hepatic Abscess or Infected Liver Cyst: These conditions can present with RUQ pain, fever, and jaundice, and require prompt diagnosis and treatment.

• Rare Diagnoses

  • Fitz-Hugh-Curtis Syndrome: A rare condition characterized by perihepatitis (inflammation of the liver capsule) due to pelvic inflammatory disease, causing RUQ pain.
  • Hepatocellular Carcinoma: A primary liver cancer that can cause RUQ pain, weight loss, and liver dysfunction, more common in patients with cirrhosis or chronic hepatitis B and C.
  • Intra-abdominal Lymphoma: Can cause RUQ pain due to liver or lymph node involvement, often accompanied by systemic symptoms like fever, night sweats, and weight loss.