Primary Sclerosing Cholangitis

What is primary sclerosing cholangitis?

Primary sclerosing cholangitis (PSC) is a disease that mainly affects the ducts that drain bile from the liver to the intestines (called the biliary tree). In PSC, these bile ducts are inflamed and narrow, preventing bile from flowing out of the liver. This can damage the bile ducts and the liver due to buildup of bile. 

The exact cause of PSC is unknown, but it is likely due to a combination of factors including genetic factors and improper function of the immune system.

What are the symptoms of PSC?

Various symptoms can be associated with disrupted bile flow and subsequent liver disease. One of the most common symptoms is itching, which is caused by buildup of bile within the liver. Yellowing of the skin or eyes (called jaundice) also can occur in PSC due to high levels of bile pigments called bilirubin. Some children may experience general symptoms of low energy, weight loss, fever, or chills. Pain in the upper right side of the abdomen also can occur. 

In some cases, children may have more severe symptoms after they develop significant liver disease, such as blood in their stool or vomit. Additionally, fluid can build up in the abdomen following progression to severe liver disease. 

In children, PSC can be associated with another form of liver disease called autoimmune hepatitis. About one in four children with PSC also have features of autoimmune hepatitis. Autoimmune hepatitis can have similar symptoms as PSC but also can involve inflammation of the liver and the bile ducts.

Children with PSC have higher likelihood of a gastrointestinal condition called ulcerative colitis, which involves diarrhea and blood in the stool. About one in ten children with ulcerative colitis are eventually diagnosed with PSC.

How is PSC diagnosed?

PSC is diagnosed based on several different sources of information. A child’s symptoms and physical exam can suggest PSC as a potential diagnosis. Certain lab tests can indicate there is bile building up in the liver. For example, bilirubin levels, as well as another blood test called gamma glutamyl-transferase, may indicate disrupted bile flow. 

A helpful imaging study to diagnose PSC is called magnetic resonance cholangiopancreatography (MRCP), which examines the bile ducts closely to look for narrowing. In addition, a procedure called endoscopic retrograde cholangiopancreatography (ERCP) may be recommended. In ERCP, physicians use a special camera called an endoscope to look at the bile ducts. 

When the bile ducts cannot be visualized well with ERCP, a special X-ray of the bile ducts called percutaneous transhepatic cholangiography (PTC) may be performed. In PTC, a needle is inserted through the skin and into the liver. Dye is injected through the needle so that the bile ducts can be seen with an X-ray. This can help identify areas of narrowing that are not easily seen on other forms of imaging.

In addition, a liver biopsy also may help with diagnosis, especially when considering other kinds of liver disease, such as autoimmune hepatitis. Liver biopsies are performed using a small needle to collect a tiny piece of liver tissue to examine under a microscope.

How is PSC treated?

A child with PSC should receive care from a pediatric gastroenterologist. Currently, there is no treatment to cure PSC.

Ursodeoxycholic acid is the most common medication for PSC. This naturally occurring bile acid works by improving bile flow from the liver and reducing liver damage from bile accumulation. Ursodeoxycholic acid should be managed by a doctor with experience treating PSC, such as a gastroenterologist or hepatologist, since there can be risks with prescribing too high of a dose. 

Another medication often used for PSC is vancomycin. Vancomycin is an antibiotic that may help regulate the healthy balance of bacteria in the gut. This can help support proper function of the immune system in PSC. Ongoing research is investigating how effective vancomycin is to treat PSC in children. In addition, children with both PSC and autoimmune hepatitis may benefit from medications that suppress their immune system.

In addition to medications, procedures also can help treat PSC. Endoscopic retrograde cholangiopancreatography (ERCP) is a procedure that may be recommended to treat narrowing of bile ducts. In ERCP, physicians use a special camera called an endoscope to look inside the upper gastrointestinal tract and access the bile ducts. During an ERCP, narrowed areas of the bile ducts can be treated by using small tools (such as balloons and stents) to help open the ducts. However, not all narrowed ducts can be treated with ERCP. Additionally, patients may experience bacterial infection of their bile ducts following ERCP, which requires treatment with antibiotics.

Ultimately, PSC can cause the liver to be severely sick or become scarred (called cirrhotic). In these cases, additional medications or procedures may be considered to treat complications of liver scaring and dysfunction. Ultimately, liver transplantation may be required, so children may be referred to a liver transplantation center to manage PSC.

Very rarely, PSC can be associated with a type of cancer of the bile ducts called cholangiocarcinoma. This happens in only ~1% of children with PSC. If this occurs, a child may be referred to a pediatric oncologist as well as a liver transplantation center for further management.

When should you seek a physician who cares for liver disease (hepatologist)?

Many pediatric patients with signs of PSC are referred to a physician who specializes in caring for liver disease, called a hepatologist. After a diagnosis of PSC is confirmed, hepatologists often manage many of the disease symptoms, including itching, jaundice, and fatigue. Hepatologists also create treatment plans and monitor disease progression to determine if the patient needs additional procedures or interventions to maintain their health. 

Authors: Minna Rodrigo, MD and Wikrom Karnsakul, MD
Editor: Christine Waasdorp, MD
February 2024