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- Jaundice.
Jaundice
Jaundice is a yellowish discolouration of the skin and the whites of the eyes.
It is caused by too much of a chemical called bilirubin in the blood.
The haemoglobin molecule in a red blood cell carries oxygen to all the cells in the body.
Each haemoglobin molecule contains four molecules of iron. The body usually separates and
recycles iron from haemoglobin molecules.
Bilirubin is a normal chemical by-product of this recycling process. The body does not need bilirubin.
Bilirubin travels through the blood to the liver. The liver converts it so that it can be removed in urine.
When a child or adult has too much bilirubin in the blood, they become jaundiced.
It takes a few days for a newborn's liver to start processing bilirubin. It may take longer in infants who
are born prematurely or who are breast-fed. About 80% of premature infants and 60% of full-term infants will
have some visible jaundice. This is a normal condition. It is not harmful and will usually go away without
treatment.
There are two main causes for too much unprocessed bilirubin. One cause is that more bilirubin is being made
than can be processed. The other cause is that the body cannot get rid of the processed bilirubin.
Sings and Symptoms:
Bilirubin pigment circulating in the blood dissolves in the subcutaneous fat causing a yellowish appearance
of the skin and whites of the eyes.
Causes:
Jaundice is not a disease. It is a symptom of a number of different diseases and disorders of the liver,
gallbladder and haemolytic blood disease. There are three main groups: obstruction, hemolysis and liver
disease.
Obstruction:
The liver normally produces about 1 litre of bile each day, which is secreted (passed) into the bile
duct system and stored in the gallbladder. The bile duct empties into the upper intestine (duodenum)
to help in digestion. Obstruction anywhere in this drainage system causes the blood levels of bilirubin
to increase, resulting in "obstructive jaundice."
Common causes of obstructive jaundice include gallstones and tumors of the pancreas or bile duct.
With gallstones, jaundice may be intermittent if the stone is not firmly stuck. Rarer causes of obstructive
jaundice include parasites such as worms, scarring from previous surgical procedures, bile duct inflammations,
and, in infancy, congenital malformations of the bile duct system.
Obstructive jaundice is often accompanied by severe irritation of the skin ('pruritus'), due to a buildup of
other bile constituents (salts) in the blood. In addition, because the bile is not entering the intestine,
the stools will be unusually pale in colour and may be bulky and smelly. This is called steatorrhea.
Haemolysis:
Much of our bilirubin is derived from the breakdown of red blood cells (which have a life of about 120 days).
When breakdown occurs too fast ("haemolysis"), the amount of bilirubin produced may swamp the liver and
drainage system, resulting in jaundice.
The bilirubin is in a different form compared with that due to obstructive causes. This is because it has not been
"conjugated" (connected to other substances) in the liver. A blood test can distinguish these two types of bilirubin
("direct" and "indirect" reactions).
Liver disease:
The other main cause of jaundice is disease of the liver itself ("hepatocellular jaundice"). The normal mechanisms for
taking the bilirubin out of the blood and transporting it into the bile duct system becomes disturbed by disease or
inflammation. Common liver diseases include infections such as hepatitis, and chronic conditions such as cirrhosis.
Causes in new born:
A baby born prematurely is more at risk to jaundice. Infection, not getting enough oxygen during birth, and some
medicines may increase the baby's risk of jaundice.
Some common causes of jaundice due to elevated levels of bilirubin include:
Blood groups incompatibility: A baby's blood type that is different from the mother's. For example, the
mother has blood type O+, and baby is B+.
Birth Trauma: A collection of blood between the scalp and the skull from pressure on the head during the birth process.
If there is a lot of blood, too much bilirubin can result.
Multiple Pregnancy: An identical twin who gets more blood than the other twin in the uterus. The baby who gets more
blood can develop jaundice after it is born.
Inherited defects of the red blood cell:
Jaundice from the baby's inability to remove bilirubin can be caused by the following conditions:
- babies with certain blood infections.
- a blockage or cyst on the baby's bile duct.
- breast-feeding.
- genetic disorders, such as Down's syndrome.
- medicines, such as antibiotics.
- thyroid abnormalities.
Treatment:
All jaundice must be evaluated. The cause of jaundice must be determined before treatment can be given.
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