jaundice Health Article

jaundice

Refers to the yellowing of skin, sclera (white of eyes), mucous membranes, and of body fluids such as urine and blood plasma.

Jaundice is caused by excess bilirubin in the blood stream. The skin, sclera (whites of the eyes), mucous membranes, urine, and blood plasma have a yellowish cast when a person has jaundice. Jaundice is not a disease, but a symptom of an underlying disease or condition.

Most bilirubin, which is a reddish pigment, is a byproduct of red blood cells. When a red blood cell dies after a lifespan of about 120 days, its components are either recycled for other uses or discarded by the body as waste. During this process, the liver combines bilirubin with another chemical to make it water soluble and discards it into the bile. The bile is then transported by the intestine out of the body.

There are several ways in which a person can become jaundiced. The most common is obstruction of bile flow through the biliary system. For example, a gallstone, a liver tumor, or a pancreatic tumor can block a biliary duct. Hemolytic jaundice occurs when the liver is overloaded with bilirubin due to anemia, incompatible blood transfusion, or extreme heat or cold. Liver cells that are damaged by hepatocellular disease (hepatitis, cirrhosis), toxins, tumors, or inflammatory conditions are unable to process bilirubin, thus preventing normal excretion.

Neonatal jaundice, especially in premature infants, is common. In fact, almost all premature infants and twothirds of full-term babies experience jaundice. Most newborns have a higher concentration of red blood cells than older infants and children. These red blood cells have a shorter lifespan, which leads to a larger amount of bilirubin available to be processed by the liver. The bilirubin accumulates—and the infant's skin yellows—as the immature liver struggles to keep up and develop the capacity to handle it. In addition, some infants develop jaundice because of an incompatibility with the mother's blood.

Jaundice is not considered particularly dangerous for infants. Some physicians advocate no treatment because the liver matures rapidly after birth and the condition usually resolves itself within days. Others believe that, because extremely elevated bilirubin levels can cause kernicterus, an often fatal brain disease, treatment is advised. Generally, infants with jaundice are treated with phototherapy, or exposure to light, which causes bilirubin near the skin's surface to decompose and become water soluble without the liver's help. The infant's eyes are covered during the procedure. Extreme cases of neonatal jaundice are treated with exchange transfusion, in which the infant's blood is gradually replaced with unaffected donor blood.

Periodicals

Caglayan, Suat, et al. "Superiority of Oral Agar and Phototherapy Combination in the Treatment of Neonatal Hyperbilirubinemia." Pediatrics 92, July 1993, p. 86.

Dennery, Phyllis A., William D. Rhine, and David K. Stevenson. "Neonatal Jaundice-What Now?" Clinical Pediatrics 34, February 1995, p. 103. Dundon, Catherine. "Newborn Jaundice." American Baby 57, July 1995, p. 8.

Lazar, Leora, Aviva Litwin, and Paul Merlob. "Phototherapy for Neonatal Nonhemolytic Hyperbilirubinemia...." Clinical Pediatrics 32, May 1993, p. 264.

Pellman, Harry. "Newborn Jaundice, or Why It's O.K. to Be Mellow Yellow." Pediatrics for Parents, June 1992, p. 4.