Jaundice

Jaundice is a condition where the skin and the eyes turn yellow due to high bilirubin levels in the blood.

Bilirubin is a product of hemoglobin degradation. Hemoglobin is the protein of the RBCs that carries oxygen to the tissues of the body. Bilirubin, after several chemical reactions, is excreted into the bile. The bile passes after that into the intestine where it is further metabolized and eliminated in the feces.

A blood test usually shows two different values of bilirubin: Unconjugated bilirubin (indirect bilirubin) and conjugated bilirubin (direct bilirubin).

It is important to know the percentage of both types of bilirubin to discern the underlying cause of jaundice.

The neonatal jaundice (jaundice in a newborn) has a different diagnostic approach and treatment.

Jaundice can be classified as:

• Prehepatic: Arise from hemolysis (excessive destruction of RBCs).
• Intrahepatic or hepatocellular: Caused by a liver damage or disease.
• Posthepatic u obstructive: Due to an impediment to the flow of bile.

The are several causes for jaundice and depends on the type of jaundice:

• Prehepatic jaundice:
  • Hemolysis: Excessive RBCs (Red Blood Cells) breakdown
  • Increased bilirubin production: Blood transfusions or hematoma resorption
  • Medication: Rifampicin, for example
  • Genetic disorders: Crigler-Najjar syndrome type 1 and 2 and Gilbert syndrome
• Intrahepatic or hepatocellular jaundice:
  • Viral hepatitis
  • Alcoholic hepatitis
  • Chronic hepatitis and cirrhosis
  • Autoimmune hepatitis
  • Drugs and other chemicals: Acetaminophen, isoniazid and other substances such as Jamaican bush tea or wild mushrooms
  • Wilson disease
  • Inherited disorders
  • Infiltrative disorders: Tuberculosis, sarcoidosis, lymphoma, amyloidosis
  • Tumors
  • Infections: Malaria, leptospirosis
• Posthepatic or obstructive jaundice:
  • Gallstones in the bile duct
  • Malignant tumors of the gallbladder, pancreas, or lymph nodes
  • Chronic pancreatitis
  • Ascariasis
  • Drugs
  • Transplant rejection
  • Inherited disorders: Dubin-Johnson syndrome and Rotor syndrome

In general, the jaundice is diagnosed when the skin and the membranes turn yellow. The underlying cause is determined following the next steps:

1. Review the medical history with the patient to find out if there are other symptoms, family or personal history (the intake of alcohol or other substances for example) or any other signs to help in the diagnosis.
   
   In case of hepatitis or bile obstruction, in addition to the yellow of the skin and the eyes, there is also dark urine (cola-colored), white stools and sometimes fever and pain.
   
   Other infections and tumors also cause fever and pain.
   
   In case of cirrhosis, there may be frequent bleeding, weight loss and altered mental status.
   
   
2. Do a physical exam to check for signs such as pain in the upper right side of the abdomen. That pain may be a sign of gallstones or pancreatitis and they are both considered an emergency.
   
   The physical exam can help to detect an enlarged and tender liver typical in acute hepatitis or a small and hard liver as a sign of cirrhosis.
   
   Other findings such as splenomegaly (enlarged spleen) or ascites (build up of fluid in the abdomen) are also helpful for the diagnosis.
   
   
3. Perform a blood test to know if bilirubin levels and other parameters related to the liver (transaminases, alkaline phosphatase, etc.) are high.
   
   
4. Check if bilirubin is the only parameter altered in the blood test or there are any other parameters altered related to the liver. Two cases are possible:
   
   
   1. Only bilirubin is high:
      
      
      • There is an increase in unconjugated bilirubin (indirect bilirubin): It can be due to a toxic substance, hemolysis, Crigler-Najjar syndrome type 1 and 2 or Gilbert syndrome.
      • There is an increase in conjugated bilirubin (direct bilirubin): It can be due to Dubin-Johnson syndrome or Rotor syndrome.
        
        
   2. Other parameters related to the liver are high:
      
      Depending on the altered parameters the cause may be hepatitis A, B or C or due to a toxic substance.
      
      After an abdominal ultrasound, gallstones or obstruction can be diagnosed.
      
      
5. If the diagnosis at this point is not conclusive, additional tests are required such as CT (computed tomography), transhepatic cholangiography and ERCP (endoscopic retrograde cholangiopancreatography) to study the bile duct.
   
   
6. The most advanced diagnostic tests include a magnetic resonance cholangiography, echoendoscopy and, finally, if it is required a liver biopsy.