S5530 Syphilitic Hepatitis Without Rash: A Diagnostic Challenge

Introduction: Syphilitic hepatitis is a rare but increasingly recognized manifestation of Treponema pallidum infection, typically occurring during secondary syphilis. While most cases present with systemic symptoms and the pathognomonic maculopapular rash, isolated hepatic involvement is uncommon and often delays diagnosis. Case Description/Methods: A 33-year-old woman presented with scleral icterus, fatigue, and markedly elevated aminotransferases (aspartate aminotransferase 1,426 U/L, alanine aminotransferase 2,524 U/L) and bilirubin (total 6.7 mg/dL). She did not have a fever, abdominal pain, or rash. Workup for viral, autoimmune, and metabolic hepatitis was unrevealing. Initial imaging was unremarkable. A syphilis screen was reactive with an RPR titer of 1:32. Liver biopsy revealed severe portal and lobular inflammation, bile duct injury, and positive immunohistochemical staining for spirochetes, confirming syphilitic hepatitis. She received intramuscular penicillin G, followed by corticosteroids due to delayed biochemical improvement. Liver enzymes normalized over several weeks. Discussion: This case highlights the diagnostic difficulty of syphilitic hepatitis when typical mucocutaneous signs are absent. Although classically cholestatic, this patient exhibited a hepatocellular injury pattern, further complicating diagnosis. Rising syphilis incidence in the U.S. underscores the importance of maintaining a broad differential for acute hepatitis. Early recognition and treatment are critical to prevent disease progression.