The Great Imitator: Syphilitic Hepatitis Presenting as a Mimic to Autoimmune Liver Disease.

Syphilis is known to mimic other disease presentations, but is seldom documented as mimicking autoimmune hepatitis with positive autoantibodies. We present a case of a 34-year-old male on pre-exposure prophylaxis (PrEP) for HIV with prior negative syphilis screening presenting with epigastric pain and constitutional symptoms. He endorsed anal sex practices with a monogamous male partner. Laboratory testing revealed elevated aminotransferases, alkaline phosphatase, and bilirubin, along with positive smooth muscle antibodies. A rapid plasma reagin and treponemal antibodies were reactive. He was treated with benzathine penicillin G with resolution of liver function derangements and autoimmune titer elevations.