Jaundice

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  • Topic: Bilirubin, Liver, Hepatology
  • Pages : 8 (2616 words )
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  • Published : April 14, 2013
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Jaundice (also known as icterus;[1] from the Greek word ίκτερος, attributive adjective: icteric) is a yellowish pigmentation of the skin, the conjunctival membranes over the sclerae (whites of the eyes), and other mucous membranes caused by hyperbilirubinemia (increased levels of bilirubin in the blood).[2] This hyperbilirubinemia subsequently causes increased levels of bilirubin in the extracellular fluid. Concentration of bilirubin in blood plasma is normally below 1.2 mg/dL (50µmol/L) leads to jaundice.[3] The term jaundice comes from the French word jaune, meaning yellow. Jaundice is often seen in liver disease such as hepatitis or liver cancer. It may also indicate leptospirosis or obstruction of the biliary tract, for example by gallstones or pancreatic cancer, or less commonly be congenital in origin (e.g., biliary atresia). Yellow discoloration of the skin, especially on the palms and the soles, but not of the sclera and mucous membranes (i.e. oral cavity) is due to carotenemia—a harmless condition[4] important to differentiate from jaundice. Contents

1 Signs and symptoms
2 Differential diagnosis
o2.1 Pre-hepatic
o2.2 Hepatocellular
o2.3 Post-hepatic
o2.4 Neonatal jaundice
3 Pathophysiology
o3.1 Hepatic events
4 Diagnostic approach
5 Complications
6 References
7 External links

Signs and symptoms

A 4-year-old boy with icteric (jaundiced) sclera which later proved to be a manifestation of hemolytic anemia due to G6PD deficiency following fava bean consumption. The main symptom of jaundice is a yellow discoloration of the white part of the eyes and of the skin. The conjunctiva of the eye are one of the first tissues to change color as bilirubin levels rise in jaundice. This is sometimes referred to as scleral icterus. However, the sclera themselves are not "icteric" (stained with bile pigment) but rather the conjunctival membranes that overlie them. The yellowing of the "white of the eye" is thus more properly termed conjunctival icterus.[5] The term "icterus" itself is sometimes incorrectly used to refer to jaundice that is noted in the sclera of the eyes, however its more common and more correct meaning is entirely synonymous with jaundice.[1][6] Differential diagnosis

When a pathological process interferes with the normal functioning of the metabolism and excretion of bilirubin just described, jaundice may be the result. Jaundice is classified into three categories, depending on which part of the physiological mechanism the pathology affects. The three categories are:

Types of jaundice
CategoryDefinition
Pre-hepatic/ hemolyticThe pathology is occurring prior to the liver.

Hepatic/ hepatocellularThe pathology is located within the liver. Post-Hepatic/ cholestaticThe pathology is located after the conjugation of bilirubin in the liver. Pre-hepatic
Pre-hepatic jaundice is caused by anything which causes an increased rate of hemolysis (breakdown of red blood cells). In tropical countries, malaria can cause jaundice in this manner. Certain genetic diseases, such as sickle cell anemia, spherocytosis, thalassemia and glucose 6-phosphate dehydrogenase deficiency can lead to increased red cell lysis and therefore hemolytic jaundice. Commonly, diseases of the kidney, such as hemolytic uremic syndrome, can also lead to coloration. Defects in bilirubin metabolism also present as jaundice, as in Gilbert's syndrome (a genetic disorder of bilirubin metabolism which can result in mild jaundice, which is found in about 5% of the population) and Crigler-Najjar syndrome. In jaundice secondary to hemolysis, the increased production of bilirubin, leads to the increased production of urine-urobilinogen. Bilirubin is not usually found in the urine because unconjugated bilirubin is not water-soluble, so, the combination of increased urine-urobilinogen with no bilirubin (since, unconjugated) in urine is suggestive of hemolytic jaundice. Laboratory findings include:

Urine: no...
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