2. DEFINITION
Jaundice — Jaundice is the yellowish discoloration of the skin and mucosa
which is caused by an abnormality of bilirubin metabolism or excretion.
Tissue deposition of bilirubin occurs only in the presence of serum
hyperbilirubinemia and is a sign of either liver disease or, less often, a
hemolytic disorder or disorder of bilirubin metabolism..
3. Differential diagnosis of jaundice
carotenoderma;
the use of drugs including quinacrine, sunitinib, and sorafenib;
Excessive exposure to phenols.
Carotenoderma, a yellow coloring of the skin,
is associated with diabetes, hypothyroidism, and anorexia nervosa, but most
commonly, it is caused by the ingestion of an excessive amounts of
vegetables and fruits such as carrots, leafy vegetables, squash, peaches, and
oranges that contain carotene.
In jaundice, the yellow coloration of the skin is uniformly distributed over the
body, whereas in carotenoderma, the pigment is concentrated on the palms,
soles, forehead, and nasolabial folds. Carotenoderma can be distinguished
from jaundice by the sparing of the sclerae
7. Approach to patient with jaundice
The bilirubin present in serum represents a balance between input
from the production of bilirubin and hepatic/biliary removal of the
pigment.
Hyperbilirubinemia may result from
(1) overproduction of bilirubin;
(2) impaired uptake, conjugation, or excretion of bilirubin;
(3) regurgitation of unconjugated or conjugated bilirubin from damaged
hepatocytes or bile ducts.
An increase in unconjugated bilirubin in serum results from
overproduction, impaired uptake, or conjugation of bilirubin. An increase
in conjugated bilirubin is due to decreased excretion into the bile
ductules or backward leakage of the pigment.
