It is a symptom complex characterized by an increase of bile pigments in body fluids and tissues. Jaundice is perceptible only when the level of bilirubin and its conjugates exceeds 1.5 mg. per 100 ml of plasma. In its mildest form, it is recognized by yellow disclolouration of sclerotics. With deeper jaundice, the skin and mucous membrane are also stained.
Normal bilirubin metabolism
- Breakdown phase: hemoglobin breakdown occurs in the reticulo-endothelial system, forming the bile pigment bilirubin, which is transported in the bloodstream attached to albumin.
- Conjugation phase Unconjugated bilirubin is conjugated by the endoplasmic reticulum enzyme of the hepatocytes, glucuronyl transferase, into bilirubin mono- and diglucuronide. These bilirubin conjugates are water-soluble and transported into the bile via specific carriers on the hepatocyte membrane. Deep jaundice is always predominantly conjugated.
- Alimentary excretion phase The bilirubin is excreted through the bile canaliculi and so reaches the intestines, where it is converted into stercobilinogen by bacterial action. A large part is reabsorbed from the intestine into portal blood and carried back to the liver and re-excreted into the bile (enterohepatic circulation of bile pigments). Stercobilinogen, which is not absorbed, is excreted in the stool.
Types of Jaundice
Jaundice is best sub-divided into unconjugated and conjugated types. Deep jaundice is always predominantly conjugated.
Causes of unconjugated jaundice
- Increased birirubin production results from any form of hemolysis, whether congenital, e.g., hereditary spherocytosis, sometimes termed ‘acholuric jaundice’ to emphasize absence of bile in urine, or acquired (e.g. malaria).
- Impaired hepatic uptake of bilirubin: Drugs are the main cause; they compete for protein binding or for the uptake receptor.
- Impairement of glucuronyl transferase: The enzyme that converts bilirubin into a water-soluble glucuronide suitable for excretion into bile is immature in premature babies, and is congenitally absent (type 1) or reduced in (type II) Crigler-Najjar syndrome. Isolated mild unconjugated jaundice in absence of liver enzyme abnormalities, almost always results from Gilbert’s syndrome
Causes of conjugated jaundice:
(a) In most cases of acquired liver disease, whether acute hepatitis cirrhosis, jaundice is or predominantly conjugated and accompanied by dark urine. (b) In most cases cholestasis is the most common pattern of drug-induced jaundice Common causes of extra-hepatic cholestasis are bile duct stones and malignant bile duct obstruction (e.g. pancreatic cancer).
Clinical classification:
3 types but combinations can occur:
Differential diagnosis of jaundice
- Hepatocellular jaundice
Acute:
Viral hepatitis
Hepatic immaturity
Drug hepatitis
Alcoholic hepatitis
Leptospirosis
Infectious mononucleosis
Yellow fever
Chronic:
- Cirrhosis
- Congenital hyperbilirubinemias
- Obstructive jaundice
Without mechanical obstruction:
Acute:
Drugs e.g. chlorpromazine
Viral hepatitis with cholestasis Pregnancy (first 3 months)
Chronic:
Primary biliary cirrhosis
With mechanical obstruction:
Intrahepatic:
Intrahepatic neoplasms and reticulosis Congenital obliteration of bile ducts Extrahepatic (Surgical jaundice):
Inside duct: Gallstones, foreign body (broken T-tube), parasites (ascaris, hydatid).
In duct wall: Congenital atresia, stricture, tumor of bile duct, sclerosing cholangitis
Outside duct Carcinoma head of pancreas or ampulla of Vater, metastasis in porta hepatis, chronic pancreatitis.
Hemolytic jaundice results from increased destruction of RBCs or their precursors in the marrow, causing increased bilirubin production. A healthy liver can excrete a bilirubin level 6 times greater than normal before unconjugated bilirubin accumulates in the blood.
Increased destruction of RBCs or their precursors in the marrow, causing increased bilirubin production (See hemolytic anemias). A healthy liver can excrete a bilirubin level 6 times greater than normal before unconjugated bilirubin accumulates in the blood.
(a) Symptoms and signs (i) Anaemia may vary from time to time developing rapidly with hemolytic crisis. (ii) Jaundice usually mild and of a lemon yellow tint. No pruritus. (iii) Pigmented gall-stones may be associated with features of chronic cholecystitis. (iv) Splenomegaly in chronic forms. (v) Ulcers or pigmentation from healed ulcers usually over the malleoli in some cases.
(b) Hematology Anaemia variable, anisocytosis, stippling, target cells. Reticulocytes increased. Leucocytosis common.
(c) Stools-Dark in colour due to increased stercobilinogen.
(d) Urine Urobilinogen increased only during crisis. Hemoglobinuria if rapid blood destruction.
(e) Serum biochemistry Serum unconjugated bilirubin raised (usually 1-3mg./100 ml. serum). Serum conjugated bilirubin slightly raised.
- Portal cirrhosis – (a) Jaundice usually slight and transient. (b) Liver enlarged, may be tender. (c) Long history of dyspeptic symptoms. (d) Hematemesis common.
- Amoebic abscess-(a) History of amoebic dysentery may be obtained. (b) Liver enlarged and tender. Compression tenderness. (c) Jaundice slight. (d) Remittent fever. (e) Excessive sweating. (f) Rapid response to metronidazole or tinidazole.
- Acute alcoholic hepatitis – History of heavy consumption of alcohol. Anorexia, weight loss, weakness and right upper abdominal pain. Jaundice. Liver enlarged and tender. Spleen may be palpable. Fever and mild anaemia.
- Drug-induced jaundice – can be in the form of acute hepatitis, cholestasis or steatosis.
- Autoimmune hepatitis-occurs typically in young women who present with jaundice of sudden onset and features of chronic liver disease. Other organs are involved and autoimmune phenomena are associated.
- Infectious mononucleosis-(a) Jaundice between 5 to 14 days after onset of illness. Mild and transient. (b) Liver seldom palpable. (c) Pyrexia persisting inspite of subsidence of jaundice. (d) Late glandular enlargement. (e) Typical blood changes. (f) Positive Paul-Bunnell test.
INVETIGATION OF A CASE OF JAUNDICE
L History:
Personal history:
More in females:
Common duct stones
Primary biliary cirrhosis
Ca gallbladder
Sex: More in males:
Ca pancreas
Liver cirrhosis
Hepatoma
Occupation: Exposure to alcohol
Infection in medical and paramedical
Sexual association:
Family history
Diseases associated with male homosexuality
Familial tendency in congenital hyperbilirubinemia
Hemolytic jaundice
Gallstones
Family contacts with other jaundiced patients
Past history
- Hepatotoxic drugs
- Blood transfusion
- Renal dialysis
- Alcohol consumption
- Biliary surgery
- Sepsis: pneumonia or urinary tract infection
Duration of jaundice
<1 month viral heaptitis
1-2 months Autoimmune hepatitis. carcinoma
>2 months Chronic liver disease
jaundice progression
Progressive melingnent obstraction
Fluctuating stone in coomon bile duct
Persistent mild jaundice of varying intensity Recurrent hemolytic episodes
Symptoms
Anorexia and weight loss Melingnacy cirrhosis
Abdominal pain colicky common duct stone
Fevar
chills and rigor
Pruritus
backache
Dry eyes/mouth