This article does not cite any sources. (June 2013) (Learn how and when to remove this template message)
|Classification and external resources|
Neonatal hepatitis is inflammation of the liver that occurs only in early infancy, usually between one and two months after birth. About 20 percent of the infants with neonatal hepatitis are infected by a virus that caused the inflammation before birth by their mother or shortly after birth. These include cytomegalovirus, rubella (German measles), and hepatitis A, B or C viruses. In the remaining 80 percent of the cases no specific virus can be identified as the cause, but many experts suspect that a virus is to blame.
Signs and symptoms
The infant with neonatal hepatitis usually has jaundice (yellow eyes and skin), that appear at one to two months of age, is not gaining weight and growing normally, and has an enlarged liver and spleen. The infant cannot absorb vitamins for proper growth.
People with neonatal hepatitis caused by rubella or cytomegalovirus are at risk of developing an infection of the brain that could lead to mental retardation or cerebral palsy. Many of these infants will also have permanent liver disease from the destruction of liver cells and the resulting scarring (cirrhosis).
Infants with giant cell hepatitis usually recover (80 percent of cases) with little or no scarring to their liver. Their growth pattern resumes as bile flows normally into the small intestine for digestion and to absorb vitamins.
About 20 percent of the infants with neonatal giant cell hepatitis develop chronic liver disease and cirrhosis. Their liver becomes very hard, due to the scarring, and the jaundice does not disappear by six months of age. Infants who reach this point in the disease eventually will require a liver transplant.
Because of the blockage of the bile ducts and the damage caused to liver cells, infants with chronic neonatal hepatitis will not be able to digest fats and will not be able to absorb vitamins A, D, E and K. The lack of vitamin D leads to poor bone and cartilage development (rickets). Vitamin A is also needed for normal growth and good vision. Vitamin K deficiency is associated with easy bruising and a tendency to bleed, whereas the lack of vitamin E results in poor coordination.
Chronic neonatal hepatitis will lead to the inability of the liver to eliminate toxins in the bile. This causes itching, skin eruptions and irritability.
In about half of all cases of neonatal hepatitis, the cause is discernible, and about 30% of cases the cause is due to a1-antitrypsin deficiency. Other causes include chromosomal abnormalities, intrauterine infections, or biliary atresia.
Infants with neonatal hepatitis caused by the cytomegalovirus, rubella or the hepatitis A, B, and C viruses may transmit the infection to others who come in close contact with the infant.
These infected infants should not come into contact with pregnant women because of the possibility that the woman will transmit the virus to her unborn child.
The jaundice is caused by the child's bile ducts becoming inflamed and enlarged, blocking the flow of bile into the small intestine for digestion of fats and absorption of vitamins. This results in the yellow pigment of bile seeping into the blood stream, causing the yellowing of the skin and eyes.
A liver biopsy is performed, where a small piece of the liver is taken out of the child with a needle and examined with a microscope. The biopsy will often show that four or five liver cells are combined into a large cell that still functions, but not as well as a normal liver cell. This type of neonatal hepatitis is sometimes called "giant cell hepatitis."
The symptoms of neonatal hepatitis are similar to another infant liver disease, biliary atresia, in which the bile ducts are destroyed for reasons that are not understood. The infant with biliary atresia is also jaundiced and has an enlarged liver, but is growing well and does not have an enlarged spleen. These symptoms, along with a liver biopsy and blood tests, are needed to distinguish biliary atresia from neonatal hepatitis.
There is no specific treatment for neonatal hepatitis. Vitamin supplements are usually prescribed and many infants are given phenobarbital, a drug used to control seizures, but which also stimulates the liver to excrete additional bile. Formulas containing more easily digested fats are also given to the infant.
Neonatal hepatitis caused by the hepatitis A virus also usually resolves itself within six months, but cases that are the result of infection with the hepatitis B or hepatitis C viruses most likely will result in chronic liver disease. Infants who develop cirrhosis ultimately will need a liver transplant.