The case of a 28-year-old man who had primary sclerosing cholangitis and autoimmune hepatitis overlapping syndrome (PSC-AIH OS) complicated by ulcerative colitis (UC) is reported. First, he was diagnosed with PSC complicated by UC and initially treated with ursodeoxycholic acid and mesalazine. Twenty-four months later, liver damage reappeared, and we performed a liver biopsy, which showed the features of AIH. We eventually diagnosed him with PSC-AIH OS complicated by UC. If liver damage worsens in PSC patients, PSC-AIH OS should be considered. The optimum management approach for PSC-AIH OS should be established.
Keywords: autoimmune hepatitis; primary sclerosing cholangitis; ulcerative colitis.