Jaundice

Introduction

Jaundice, also known as icterus, is a condition which is characterised by a yellowish discolouration of the skin and the whites of the eyes. It is a symptom or clinical sign, not a disease by itself. The yellow colouration is caused by an excess amount of the bile pigment known as bilirubin in the body. Normally, bilirubin is formed by the breakdown of haemoglobin during the destruction of worn-out red blood cells. The pigment is then excreted by the liver into the bile via the bile ducts.





Cause and Pathogenesis

Excess amounts of bilirubin in the body can be caused by the overproduction of bilirubin, the failure of the liver cells to metabolise or excrete the bilirubin produced, or a blockage of the bile ducts. Overproduction of bilirubin may be caused by the destruction of an unusually large number of red blood cells, which occurs in a condition known as haemolytic anaemia. In this condition the liver cannot excrete the bilirubin which is formed more rapidly. This may occur in diseases such as malaria, thalassemia, and haemolytic disease (due to destruction of the red blood cells) of the new-born . Often, mild jaundice occurs as a common and normal condition in new-born babies because at birth there is both a deficiency in the enzyme that helps to eliminate bilirubin and also an increased breakdown of red blood cells (RBC) in the body. In babies, the condition generally disappears within a few days after birth as the enzyme is formed in the body. Sometimes, deficiency of this enzyme can also cause jaundice in adults. Jaundice may also result from various diseases or conditions that can affect the liver, such as hepatitis, cirrhosis, or cancer. A blockage of the bile ducts, may cause jaundice. The ducts may be blocked by various factors including inflammation and infection (cholangitis), gallstones (cholelithiasis), or cancer of the pancreas or the common bile duct.

The clinical types of jaundice include haemolytic jaundice which is due to the breakdown of RBC; hepatocellular jaundice caused by hepatic pathology due to viruses, drugs, alcohol abuse, etc; and Cholestatic jaundice due to biliary tract obstruction.

There are various strains of hepatitis viruses including hepatitis A (HAV), hepatitis B (HBV), hepatitis C (HCV), hepatitis D (HDV), and hepatitis E (HEV). Viruses F and G also exist and may cause primary hepatitis. HAV is transmitted by contaminated food and water and by the faecal-oral route; HBV and HDV are transmitted by contact with bodily fluids, HCV by percutaneous exposure to blood, and HEV, by contaminated water and by the faecal-oral route. Hepatitis A is seen most often in children and young adults, but the incidence is rising among those who are HIV positive. Hepatitis B affects all age groups and is associated with blood transfusion. Hepatitis C accounts for most transfusion-related cases. It is seen in all age groups. Hepatitis D is seen in individuals who are susceptible to HBV or may be HBV carriers, such as haemophiliacs and IV drug users. The disease manifestation is severe in children. Hepatitis E is seen primarily among young adults in developing countries. It is most severe in pregnant women. Congenital non-haemolytic hyperbilirubinemia such as Gilbert's Syndrome also causes jaundice. Sometimes certain drugs such as chlorpromazine (an anti-psychotic drug) may inhibit bilirubin excretion by the liver, causing jaundice.





Symptoms and Signs

The main symptoms of jaundice are the characteristic yellowish colour of the skin, sclera (whites) of the eyes, nail beds and tongue. Other symptoms usually depend on the actual cause of the jaundice. In some types of jaundice, bilirubin is excreted in the urine, which becomes yellowish brown in colour. If the excretion of bile is obstructed, stools are almost white and the digestion of fat is consequently impaired. If the jaundice has been present for a long time, pruritis (intense itching) may occur. In jaundice, due to obstruction, lipid deposits on the skin such as xanthelesmas on the eyelids or xanthomas can develop. Some patients with jaundice may also have vomiting, and abdominal pain, malaise, severe weakness etc. Complications include hepatic failure with its attendant complications such as bleeding, vomiting of blood, accumulation of fluid in the abdomen (ascites), and a condition called hepatic encephalopathy where the patient has altered consciousness and later coma. Fulminant hepatic failure and hepatic coma may often be fatal even with treatment. Another complication of hepatitis is the development of cirrhosis (due to destruction of the liver cells) and also conditions such as chronic active hepatitis wherein the jaundice may persist for several months. The prognosis in these conditions may be poor although the results are better with prompt and effective treatment.





Investigations and Diagnosis

Diagnosis of jaundice requires blood tests, which determine whether the liver is diseased, whether the bilirubin is metabolised normally by the liver cells, and if there is any abnormal breakdown and destruction of the red blood cells. Blood tests will also indicate any obstruction present. Hyperbilirubenaemia (increased serum levels of bilirubin) is present. The normal total of serum bilirubin is about 2-17 micro-mol/l(<1 mg/dl). The urine is examined for the presence of bile salts, bile pigments and urobilinogen. The faeces is examined for pale colouration, which usually indicates an obstruction to bile excretion. The diagnosis of hepatitis is based on the clinical history and various laboratory tests. In HAV, the stool is positive for the virus two to four weeks after exposure, and the enzyme-linked immunosorbent assay (ELISA) shows a rise in HAV antibodies. In HBV, serum antigen tests detect HBsAg, as well as a series of antibodies such as anti-HBe. A serum test for HCV can also be done. A liver biopsy may be done, for indications of cellular changes or pathology. Ultrasonogram can be done to examine the liver, gallbladder, and bile ducts to detect obstructions and locate gallstones. ERCP is done to detect abnormalities in the biliary tract and pancreas. Liver function tests are done to detect hepatic abnormalities. For some pancreatic pathologies, abdominal CT Scans or MRIs may be required.





Treatment and Prognosis

Treatment consists mainly of treating the underlying cause (if treatable) and in providing supportive therapy. The basic pathology or disease responsible for the jaundice should be diagnosed and treated. Obstructive jaundice can be relieved by removing the cause of the blockage such as gallstones, by surgical intervention. Haemolytic jaundice is treated by drugs that target the cause of the haemolysis (e.g., malaria), and by other therapy such as blood transfusion. It is important to stop the intake of the drugs or toxic chemicals or alcohol that may be responsible for the jaundice. Proper diet and nutritional supplements are also important in preventing the condition from worsening. Vitamin K injections may need to be given to prevent bleeding.

Prevention


The most important step in prevention of Hepatitis B infection is vaccination. Three doses of the vaccine need to be given at intervals of one month each or alternately two doses may be given at monthly intervals followed by the third dose at the sixth month. The immunity lasts for five years and booster doses are required after that period. It is important to avoid causes of liver disease such as alcohol abuse, drugs, and toxins. Prompt treatment of underlying hepatic disorders or pathology is essential to prevent or minimise permanent damage to the liver.