The Great Pretender: early syphilis mimicking acute sclerosing cholangitis

A 36-year old man with known HIV infection presented to an outpatient genitourinary service with jaundice, rash and sore throat. Investigations revealed marked biochemical abnormalities, including alkaline phosphatase and alanine transaminase >10 times the upper limit of normal. Liver ultrasound was normal, but stricturing and beading of the intrahepatic biliary tree was seen on magnetic resonance cholangiopancreatography (MRCP), similar to changes associated with sclerosing cholangitis. Serological syphilis antibodies were detected with a positive immunoglobulin M (IgM) and rapid plasma reagin of 1:128, in keeping with early infection. Liver biopsy showed large bile duct obstruction with portal oedema, bilirubinostasis and neutrophil polymorph infiltration around proliferating ductules; specific stains for spirochaetes were negative. Symptoms and biochemical markers improved rapidly after treatment for secondary syphilis with oral steroids and intramuscular benzathine penicillin. A repeat MRCP 18 months post syphilis treatment showed resolution. This case illustrates syphilis presenting as acute sclerosing cholangitis.