The bacterium Treponema pallidum causes the sexually transmitted infection known as syphilis. This infection can damage the liver, a complication called syphilitic hepatitis. This occurs when the bacteria spreads throughout the body and inflames the liver tissue. While it is an uncommon manifestation, recognizing syphilitic hepatitis is important because it is a highly treatable cause of liver dysfunction that can lead to serious health issues if left untreated.
Syphilis Stages and Liver Involvement Risk
The risk of liver involvement changes as the syphilis infection progresses. Liver enzyme abnormalities are common in early syphilis, but symptomatic syphilitic hepatitis is rare, estimated to occur in less than 3% of cases. The primary stage, characterized by a localized, painless sore called a chancre, rarely involves the liver.
Liver involvement is most frequent during the secondary stage, which begins weeks to months after the initial infection. This stage is marked by the systemic dissemination of Treponema pallidum throughout the bloodstream, often resulting in a body-wide rash and flu-like symptoms. The bacteria can directly infiltrate the liver tissue or cause inflammation through an immune-mediated response, leading to acute syphilitic hepatitis.
In late or tertiary syphilis, which can manifest years after the initial infection, liver damage can occur, though it is less common than in the secondary stage. Damage in this late phase is often due to the formation of gummas. These are soft, tumor-like masses of inflammation that develop in the liver, causing localized tissue destruction that may be mistaken for other types of tumors.
Clinical Presentation of Syphilitic Hepatitis
Syphilitic hepatitis often presents with non-specific symptoms, earning syphilis the nickname “the great imitator.” Patients may experience systemic signs such as fatigue, malaise, and fever, often alongside the characteristic non-itchy rash of secondary syphilis. Liver-specific symptoms include abdominal pain, particularly in the upper right quadrant, and sometimes jaundice (a yellowing of the skin and eyes).
Laboratory tests reveal a distinctive pattern of liver enzyme abnormalities. The most noticeable finding is a disproportionate elevation of alkaline phosphatase (ALP), which is significantly higher compared to the transaminases, aspartate transaminase (AST) and alanine transaminase (ALT). This pattern suggests a cholestatic injury, meaning the flow of bile within the liver is obstructed or impaired.
The underlying pathology involves liver inflammation (hepatitis), where a biopsy would show non-specific features like inflammation around the portal areas and occasionally granulomas. In tertiary syphilis, localized gummas represent a form of destructive inflammation. These lesions can present as mass lesions on imaging studies, complicating the diagnosis by mimicking malignant tumors.
Diagnosis and Resolution of Liver Damage
Confirming a diagnosis of syphilitic hepatitis requires a combination of clinical evidence, specific laboratory findings, and the exclusion of other causes of hepatitis. The first step involves serological testing for syphilis, which typically includes a non-treponemal test, such as the Rapid Plasma Reagin (RPR) or VDRL test, to screen for active infection. A positive screening test is then confirmed with a treponemal test, like the Fluorescent Treponemal Antibody Absorption (FTA-ABS) or T. pallidum Particle Agglutination (TPPA) assay.
The diagnosis is suggested when positive serological results are paired with characteristic liver enzyme abnormalities, especially the disproportionately high alkaline phosphatase. Imaging studies may assess the liver, particularly to evaluate for gummas in tertiary syphilis. A liver biopsy is usually not required, as confirmation often relies on the rapid improvement of liver function following treatment.
The standard treatment for syphilitic hepatitis, regardless of the stage, is an appropriate course of antibiotics, with penicillin G being the medication of choice. For early stages of syphilis, a single intramuscular dose of 2.4 million units of benzathine penicillin G is typically effective. Upon initiation of treatment, patients often experience a rapid improvement in both their systemic symptoms and liver enzyme levels. Post-treatment monitoring, including follow-up serological testing and repeat liver function tests, is necessary to ensure the infection has been eradicated and the liver damage has resolved completely.