A 50-year-old man with a history of chronic Hepatitis B presents with right upper quadrant pain, jaundice, and dark urine. His Hepatitis B had been well controlled on entecavir. Lab tests show significantly elevated liver enzymes. What is the likely diagnosis and next steps?
This patient may be experiencing a flare of Hepatitis B, which can sometimes happen even on antiviral therapy, or potentially drug resistance. Another possibility is a superimposed liver disease such as alcoholic or autoimmune hepatitis. Further evaluation should include a Hepatitis B DNA level, antiviral resistance testing, and other tests for additional liver diseases based on the clinical context.