Clinical Reasoning Jaundice

Summary

Jaundice, a condition marked by yellowish skin and sclera, occurs when bilirubin levels exceed 2 mg/dL in adults. It can be classified into prehepatic, hepatocellular, or posthepatic types based on the underlying cause. Prehepatic jaundice often results from hemolytic anemia, hepatocellular jaundice from liver dysfunction (such as genetic conditions like Gilbert and Dubin-Johnson syndromes), and posthepatic jaundice from biliary obstructions like stones or cancers. Diagnosis involves blood tests, imaging, and sometimes genetic testing, while treatment varies from managing underlying diseases to surgical interventions in cases of obstruction or cancer.

Takeaways

• 😀 Jaundice is characterized by yellowing of the skin and sclera, typically due to elevated bilirubin levels in the blood.
• 😀 Total bilirubin levels above 2 mg/dL in adults indicate jaundice, which can be categorized as prehepatic, hepatocellular, or post-hepatic.
• 😀 A thorough workup for jaundice includes testing for total and conjugated bilirubin, ALT, alkaline phosphatase, albumin, and PT/INR to assess liver function.
• 😀 Prehepatic jaundice occurs due to excess unconjugated bilirubin, often caused by conditions like hemolytic anemia or ineffective red blood cell production.
• 😀 Gilbert Syndrome is a common genetic cause of prehepatic jaundice, where a deficiency in an enzyme impairs bilirubin conjugation, typically triggered by fasting or stress.
• 😀 Hepatocellular jaundice is caused by liver dysfunction, where bilirubin metabolism is disrupted. It may result from conditions like Gilbert Syndrome or liver injury from medications.
• 😀 Dubin-Johnson Syndrome and Rotor Syndrome are two benign genetic conditions leading to conjugated hyperbilirubinemia and mild jaundice due to issues with bilirubin transport.
• 😀 Post-hepatic jaundice is caused by biliary obstruction, often due to gallstones, pancreatic cancer, or biliary tract tumors, leading to an accumulation of conjugated bilirubin in the blood.
• 😀 In post-hepatic jaundice, common symptoms include right upper quadrant pain, clay-colored stools, and dark urine due to the inability to excrete bilirubin into the intestines.
• 😀 Diagnostic tests for post-hepatic jaundice include abdominal ultrasound, MRCP, and ERCP to detect bile duct obstructions and remove any blockages if necessary.

Q & A

What is jaundice and what causes it?

Jaundice is the yellowing of the skin and sclera (eyes), caused by an excess of bilirubin in the bloodstream. It occurs when bilirubin levels exceed 2 mg/dL in adults, and can result from prehepatic, hepatocellular, or post-hepatic causes.

What are the main causes of prehepatic jaundice?

Prehepatic jaundice is caused by the overproduction of unconjugated bilirubin, typically due to hemolytic anemia or conditions like dysarthropoiesis, where the body destroys red blood cells at an abnormal rate.

How is prehepatic jaundice diagnosed?

Diagnosis includes testing for elevated total bilirubin with normal conjugated bilirubin levels. Additional labs like CBC, LDH, haptoglobin, and a blood smear are used to identify hemolysis or red blood cell destruction.

What is Gilbert Syndrome, and how does it relate to jaundice?

Gilbert Syndrome is a genetic condition that leads to a decrease in the enzyme responsible for conjugating bilirubin in the liver. It results in mild unconjugated hyperbilirubinemia, typically triggered by fasting or stress, but is usually benign and requires no treatment beyond maintaining normal caloric intake.

What laboratory tests help diagnose hepatocellular jaundice?

Hepatocellular jaundice is diagnosed by elevated total and conjugated bilirubin levels along with liver injury markers such as ALT and AST. Additional tests for viral hepatitis, autoimmune hepatitis, and liver function are also necessary.

What are some common genetic causes of hepatocellular jaundice?

Genetic conditions such as Dubin-Johnson syndrome and Rotor syndrome can cause hepatocellular jaundice. Both conditions impair bilirubin transport within the liver, leading to the accumulation of conjugated bilirubin.

How is Dubin-Johnson syndrome different from Rotor syndrome?

While both conditions involve conjugated hyperbilirubinemia, Dubin-Johnson syndrome is characterized by a black liver pigment on biopsy, while Rotor syndrome does not show this pigment. Both conditions are benign and require no specific treatment.

What causes post-hepatic jaundice, and how is it diagnosed?

Post-hepatic jaundice is usually caused by an obstruction in the biliary tree, preventing bilirubin excretion. Diagnosis involves elevated total and conjugated bilirubin levels with high alkaline phosphatase levels, and imaging tests like ultrasound or MRI to detect blockages.

What conditions can lead to biliary obstruction causing post-hepatic jaundice?

Biliary obstruction can be caused by gallstones, cholangiocarcinoma (bile duct cancer), pancreatic cancer, or primary sclerosing cholangitis. These conditions block the bile ducts, preventing the normal flow of bilirubin into the intestines.

What treatments are available for jaundice caused by biliary obstruction?

Treatment for biliary obstruction depends on the underlying cause. For gallstones, endoscopic procedures like ERCP can remove stones. For tumors, surgery to remove the obstruction or parts of the liver may be necessary, followed by chemotherapy or radiation for cancers.