Syphilitic Hepatitis Presenting As Cholestatic Liver Injury: A Case Report

Syphilis, caused by the spirochete Treponema pallidum, is a sexually transmitted infection whose incidence has risen worldwide over the past decade and which may involve virtually any organ, including the liver. Syphilitic hepatitis is an uncommon and frequently overlooked manifestation that characteristically produces a cholestatic pattern of liver injury. We report the case of a 61-year-old man with no relevant medical history and self-reported sexual risk factors, admitted with a 15-day history of bilateral leg edema, fatigue, dry cough, odynophagia, weight loss, and conjunctivitis of the right eye. He denied alcohol consumption and the use of herbal products, dietary supplements, and recreational drugs. Examination revealed erythematous macular lesions on the trunk and limbs sparing the palms and soles, anterior cervical lymphadenopathy, bilateral leg edema, and jaundice, with no palpable hepatomegaly, splenomegaly, or ascites; ophthalmologic assessment excluded uveitis. Laboratory testing showed a cholestatic pattern of liver injury, with alkaline phosphatase and gamma-glutamyl transpeptidase levels of 895 and 981 U/L, respectively, disproportionately elevated compared with alanine aminotransferase and aspartate aminotransferase levels of 103 and 84 U/L, respectively, together with a total bilirubin of 3.16 mg/dL. Serologic tests for hepatitis A, B, C, and E viruses, cytomegalovirus, Epstein-Barr virus, and human immunodeficiency virus were negative, as was a comprehensive autoantibody panel; the iron profile and N-terminal pro-B-type natriuretic peptide were unremarkable. Abdominal ultrasonography and magnetic resonance cholangiopancreatography showed mild hepatomegaly without focal lesions or biliary dilatation. The Venereal Disease Research Laboratory (VDRL) test was reactive at a titer of 1/128, and anti-Treponema pallidum IgG was positive. Secondary syphilis with hepatic involvement was diagnosed, and the patient received a single intramuscular dose of 2.4 million IU of benzathine penicillin G. Symptoms resolved, and liver biochemical parameters largely normalized within six months. This case underscores the need to consider syphilis in the differential diagnosis of unexplained cholestatic liver injury, particularly in patients with risk factors for sexually transmitted infections.