Jaundice is not to be confused with xanthochromia, in which the skin turns orange from carotene deposits but the sclerae remain normal in appearance. Carotenemia is often seen in hypothyroidism and diabetes mellitus, but jaundice is not usually a complication of these two conditions.
The causes of jaundice can best be established by applying physiology (Table 42). Jaundice develops from hyperbilirubinemia, and may not be noticed until the bilirubin exceeds 3 or 4 mg/dL. Hyperbilirubinemia is due to an increased production of bilirubin, impaired transport of bilirubin to the liver for excretion, and decreased excretion of bilirubin.
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Jaundice |
1. Increased production. Bilirubin is produced by the release of hemoglobin from the red cells and its subsequent breakdown. Thus, the hemolytic anemias are the principal causes of this category of jaundice. These include hereditary spherocytosis, Cooley anemia, septicemia, autoimmune hemolytic anemia, and malaria.
2. Impaired transport. Congestive heart failure (CHF) is the principal cause of this form of jaundice, but it must be advanced enough to cause cardiac cirrhosis.
3. Decreased excretion. This group of causes of jaundice is divided into conditions in which the liver is unable to transform unconjugated bilirubin to the conjugated form, such as Gilbert disease, infectious hepatitis, and cirrhosis; conditions in which the liver cannot transfer the conjugated bilirubin into the bile ducts, such as Dubin–Johnson syndrome; and conditions that obstruct the bile ducts, such as common duct stones, cholangitis, chlorpromazine toxicity, and carcinomas of the pancreas and ampulla of Vater.
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TABLE 42. Jaundice |
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Approach to the Diagnosis
The accurate diagnosis of jaundice is established by the association of other symptoms and the performance of liver function and special diagnostic procedures. For example, jaundice with fever, a prodromal phase of anorexia, malaise, and a tender liver suggests hepatitis. Jaundice with itching suggests xanthomatous or primary biliary cirrhosis. Jaundice and anemia suggest hemolytic anemia. Jaundice, back pain, and an abdominal mass suggest a carcinoma of the pancreas.
When liver functions show only an elevated indirect bilirubin level, Gilbert disease or hemolytic anemia is suggested. A normal urine urobilinogen will make Gilbert disease even more likely. Liver function analyses showing only elevated bilirubin and alkaline phosphatase levels suggest bile duct obstruction by a stone or tumor. Liver function results showing an impressive elevation of the bilirubin, serum aspartate aminotransferase, and serum alanine aminotransferase levels suggest hepatitis.
In cases in which obstruction versus parenchymal disease remains a dilemma after routine tests, several newer procedures have been developed that may help avoid an exploratory laparotomy. Endoscopic retrograde cholangiopancreatography (ERCP), cutaneous transhepatic cholangiography, and peritoneoscopy are very useful in these cases. Computed tomography (CT) scans and ultrasonography are also valuable. The old steroid whitewash is still useful. This is done by administering 20 mg of prednisone daily for 5 days and monitoring the bilirubin level. A positive test, indicating parenchymal diseases, is considered a drop of the bilirubin to one half its original value or more. Exploratory laparotomy may be necessary despite an extensive workup.
Other Useful Tests
1. Complete blood count (CBC) (hemolytic anemia, infection)
2. Chemistry panel (hepatitis, e.g.)
3. Hepatitis panel (viral hepatitis)
4. Febrile agglutinins (Salmonella, brucellosis)
5. Monospot test (infectious mononucleosis)
6. Cytomegalic virus antibody titer (cytomegalic inclusion disease)
7. Leptospirosis antibody titer (leptospirosis)
8. Antinuclear antibody (ANA) analysis (lupoid hepatitis)
9. Serum iron and iron-binding capacity (Wilson disease)
10. Serum haptoglobins (hemolytic anemia)
11. Hemoglobin electrophoresis (hemolytic anemia)
12. Sickle cell prep (sickle cell anemia)
13. Blood smear for malarial parasites (malaria)
14. Gallbladder sonogram (cholelithiasis)
15. Peritonoscopy and biopsy (neoplasm, cirrhosis)
16. Antimitochondrial antibodies (biliary cirrhosis)
17. Gastroenterology consult
18. Magnetic resonance cholangiopancreatography (common duct stone)
19. ERCP (common duct stone)
Case Presentation #59
A 26-year-old intern complained of loss of appetite, fever, and malaise for 1 week prior to admission. On the day of admission, he is noted to have icteric sclera.
Question #1. Utilizing your knowledge of physiology, what is your differential diagnosis?
He denies alcohol or intravenous drug abuse. He has not been exposed to anyone with hepatitis in the past 3 months. However, he did start taking ranitidine hydrochloride for heartburn a few days prior to the onset of symptoms. Physical examination revealed icteric sclera and slightly enlarged tender liver.
Question #2. What is your diagnosis now?
