Differential Diagnosis for 66 yo Female with Diffuse Itching and Abnormal Liver Enzymes

• Single Most Likely Diagnosis
  • Primary Biliary Cholangitis (PBC): The patient's symptoms of diffuse itching with a normal skin exam, elevated alkaline phosphatase, and mildly elevated transaminases are consistent with PBC, an autoimmune disease that primarily affects the bile ducts in the liver.
• Other Likely Diagnoses
  • Drug-induced liver injury: Although the patient only drinks a small amount of wine daily, other medications or substances could be contributing to her liver enzyme elevations and symptoms.
  • Chronic viral hepatitis (despite negative Hepatitis B/C serologies, there could be a false negative or another hepatitis virus): It's essential to consider other types of hepatitis or recheck serologies to rule out any potential false negatives.
  • Non-alcoholic fatty liver disease (NAFLD): Given the patient's age and the presence of elevated liver enzymes, NAFLD is a possibility, although the itching is less commonly associated with this condition.
• Do Not Miss Diagnoses
  • Cholestasis due to pancreatic cancer: Itching can be a symptom of cholestasis, which can be caused by obstruction of the bile ducts by a tumor. Although less likely, this diagnosis is critical to rule out due to its severe implications.
  • Hematologic malignancies (e.g., lymphoma): Some lymphomas can cause itching and abnormal liver function tests, making this a crucial diagnosis not to miss.
• Rare Diagnoses
  • Intrahepatic cholestasis of pregnancy (unlikely given the patient's age): Although extremely rare in postmenopausal women, it's a condition that could potentially cause similar symptoms.
  • Sarcoidosis: This autoimmune disease can affect multiple organs, including the liver, and cause a variety of symptoms, including itching and abnormal liver enzymes. However, it's less common and would typically be associated with other systemic symptoms.