Icterus or jaundice is yellowing of skin (skin and mucous membranes: this is called jaundice mucocutaneous) due to the accumulation of bilirubin, which may be free or combined so there are two types of jaundice :
* Jaundice with free bilirubin
* Jaundice in conjugated bilirubin
Jaundice may be more or less intense, but when it starts is only visible in the conjunctiva of the eye ( "white of the eye). It must be sought in natural light.
Red blood cells have a lifespan of about 120 days. At the end of this period, they are destroyed in the spleen, which produced bilirubin free. The free bilirubin is toxic and can be harmful, in a healthy individual, it is then transformed by the attachment to albumin conjugated bilirubin into nontoxic. This substance gives its yellow color to urine and feces.
Icterus or jaundice is caused by excessive bilirubin (which may be free or conjugated) in human blood.
Bilirubin is the degradation product of heme (a constituent of hemoglobin) transported in the blood in association with albumin to the liver where it is picked up by liver cells (hepatocytes) and then conjugated and excreted in the bile by them to be removed in the stool.
Bilirubin is known to free hepatic conjugation, and then combined. The conjugated bilirubin is soluble, it can be filtered by the kidney: jaundice with conjugated bilirubin will then result in dark urine and pruritus as a bilirubin may be deposited in the skin.
There are jaundice at any age of life and for many reasons:
Jaundice in Babies
The neo-natal jaundice is common.
For reasons not understood, it appears that a baby with jaundice have a higher risk of developing testicular cancer later.
Several causes can explain the jaundice of the newborn
Jaundice with free bilirubin
* Jaundice called "physiological"
It is due to the immaturity of the liver at birth: the newborn has a very large number of red blood cells containing hemoglobin F (fetal) blood to be replaced by blood for the purpose of hemoglobin A (adult). This causes hemolysis (destruction of red blood cells) important in a very short time! The liver is sometimes not well developed enzymatic equipment to transform any free bilirubin, which will then accumulate and cause jaundice.
* Jaundice mother's milk:
Jaundice little intense observed in children breastfed, and that extends the duration of breastfeeding. You can make the diagnosis by heating milk at 60 ° C prior to giving the child the jaundice disappears.
* The hemolytic jaundice:
In newborns, it can even find pathological causes. The risk is that the accumulation of bilirubin is such that it becomes nerve: indeed, at a certain rate, bilirubin crosses the blood-brain barrier and severely affects the brain, causing jaundice nuclear achievement of basal ganglia of the brain.
o Rh incompatibility between mother and child: if the higher risk of jaundice intense: the mother is Rh - Rh + children, with presence of antibodies antidepressants in the mother. The child will therefore hemolysis due to contact with maternal blood at delivery.
ABO incompatibility o: mother group O, Child A, B or AB
o infectious jaundice: due to an infection of the newborn
o diseases of red blood cells: deficiency G6-PD disease Minkowski-driver
o jaundice due to resorption of haematomas significant bump serum blood cephalhematome ...
Jaundice with conjugated bilirubin
* Cholestatic jaundice: rare in the newborn
The treatment of jaundice in the newborn
* For a slight jaundice: expose the child to daylight (not direct sunlight), and the nurse do much to promote éliminitation of bilirubin through the stool and urine.
* Phototherapy: placing the child with protection layer in ophthalmic lamps emitting light in the blue spectral region between 400 and 550 nm, so that light degrades bilirubin
* Medicines enzyme inducers, albumin infusion
* Exchange transfusion: severe jaundice with nuclear jaundice risk: they have to remove the blood of the child (exsanguiner) and replaced by a pocket of blood (transfusion). This is done gradually, in 5ml of 5ml.
Jaundice with free bilirubin
* Hemolysis: destruction of red blood cells causing an excess production of bilirubin. We found anemia in the patient.
The hemolysis can occur in cases of infection with sepsis (blood cultures if fever) in the event of illness immunoallergique (Coombs test) in case of drug (check all medications taken recently. Regression of jaundice after stopping medication causal) in case of mechanical barrier (heart valve, arterio-venous fistula; schizocytes presence of) ...
* Gilbert's disease Gilbert's syndrome, despite the uptake of bilirubin by liver cells, there was a lack of conjugation of it is due to an enzyme deficiency glucuronyltransferase.(W3C)
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