Jaundice is the yellow tinge of the skin, sclera (whites of the eyes) and inside of the mouth that arises when the bilirubin level in the blood is higher than normal. While it is often referred to as “yellow jaundice”, the word jaundice in itself means yellow tinge. Jaundice is more often seen in newborn babies but can also occur in adults as a result of liver and blood disorders.
Causes of Jaundice
Jaundice occurs when the bilirubin levels in the blood rises to a higher than normal level. In order to understand the cause of jaundice, a basic knowledge of bilirubin is necessary. The body breaks down red blood cells (erythrocytes) in our body every 120 days or so (in children this may be every 70 to 80 days). Haemoglobin is released from the red blood cells and this is further broken down by macrophages, a type of immune cell in the blood. Bilirubin is released from these macrophages as one of the end products of haemoblogin breakdown – this type of bilirubin is known as unconjugated or free bilirubin. It quickly reaches the liver where it is taken up by the liver cells known as hepatocytes.
Within the liver cell, it is bonded to other compounds to form conjugated bilirubin and this process is catalyzed by the enzyme glucuronyl transferase. The conjugated bilirubin is then passed out into the bile which is stored in the gallbladder and pushed out into the small intestine. Bile is necessary to break down fats in the food that we eat and eventually this bilirubin is passed out with our stool – in fact, it gives stool the typical brown color. Some bilirubin is passed out in the urine as well. In this way the body manages the bilirubin levels in the blood stream.
In jaundice, however, the bilirubin levels in the blood builds up significantly. This is known as hyperbilirubinemia. Either unconjugated or conjugated bilirubin may rise in the blood and this varies depending on the types of disease disturbing the bilirubin conjugation and excretion process.
Jaundice in Babies
In babies, jaundice may occur soon after birth and not be due to any disease. This is known as physiologic jaundice and usually arises 4 to 7 days after birth. It is a due to the liver’s inability to conjugate bilirubin but this ability is quickly established after birth. Furthermore, red blood cells are rapidly broken down in the newborn because it is in excess so there is a sudden flood of bilirubin in the blood due to this process.
Breast feeding and breast milk may also cause jaundice due to different mechanisms – this is not a reason to stop breastfeeding and will pass after a short while without any serious complications. Breastfeeding and breast milk jaundice is known as non-physiologic jaundice and is not due to any life-threatening disease. However, there are some serious conditions that may cause prolonged jaundice in babies. These are usually related to genetic defects that affect the enzyme glucuronyl transferase like type 1 Crigler-Najar syndrome and Gilbert’s syndrome. Or it may be due to a blood incompatibility between mother and chile known as erythroblastosis fetalis.
Jaundice in Adults
In adults, the cause of jaundice is usually more serious. Gallstones are the most common cause when it blocks the outflow of bile from the gallbladder and liver. This prevents the body from dumping the bilirubin out with the bile and it is either resorbed back into the blood or not passed out from the blood at all. Gallstones can be easily treated. Other liver diseases like alcoholic liver disease, liver cancer, liver disorders secondary to conditions like heart failure or even HIV/AIDS, and infections like hepatitis may all cause jaundice. Blood disorders, particularly hemolytic anemias, where the red blood cells are rapidly broken down may also lead to jaundice.
Symptoms of Jaundice
Jaundice is a sign of an underlying disorder and is not a disease on its own. The yellowish discoloration is first seen in the eyes and face. It becomes evident in the rest of the body, particularly the upper body, over time and as the bilirubin levels in the blood increases further. Jaundice may also be accompanied by itching of the skin (pruritis) as bilirubin deposited in the skin causes irritation. If left untreated, jaundice may lead to a dangerous brain condition known as kernicterus.
Treatment of Jaundice
In babies, the main approach to treatment is through UV phototherapy. This requires the baby to be exposed to ultraviolet light, usually within an incubator. Sunlight is not advisable although it may help to some extent. Feeding, either breast milk or formula, should be increased in babies with jaundice and supplementation with water and glucose solutions are not advisable. In most cases of neonatal jaundice, treatment is usually not necessary and will pass with time in cases of physiologic and non-physiologic causes.
In pathological cases of jaundice – jaundice due to disease processes – the treatment should be directed at the cause. In terms of gallstones, the most common cause of jaundice in adults, removal of the stones will be necessary. The treatment is much more complex when jaundice arises from liver diseases, infections or hemolytic anemias. Phototherapy is usually not significantly effective in adults.