Definition of jaundice
Jaundice, or jaundice in medical language, is a yellow coloring of the skin and mucous membranes (coatings that line the body cavities). Its intensity can be more or less important and it often begins with a yellow color of the white of the eye.
This particular hue is due to the accumulation in the blood of a protein, bilirubin, which is a product of degradation of another protein contained in the red blood cells, hemoglobin, which is responsible for transporting oxygen to the organs of the human body.
Indeed, red blood cells are regularly renewed. They form in the bone marrow and, after 120 days, are destroyed in the spleen. The so-called free bilirubin, which is derived from the hemoglobin then released, then goes to the liver where it is modified (bilirubin conjugated with glucuronic acid), so as to become soluble in water and to be eliminated by the kidney and the digestive tract. It is the conjugated bilirubin which thus gives the yellow color of the urine.
In different circumstances, however, there may be an excess of bilirubin which is then responsible for jaundice.
Risk factors for jaundice
In adults, the risk factors for jaundice are represented by:
- Excessive alcohol consumption may be responsible for alcoholic hepatitis and cirrhosis of the liver decreasing liver function.
- Some drugs are also likely to damage the liver, and toxic (fungi for example).
- A diet too rich in fat is also known to promote the formation of stones in the bile ducts because they are formed by the crystallization of cholesterol.
- Viral hepatitis: In the absence of vaccination against hepatitis A and B, the risk of contracting these infections is increased in the developing country (water contamination for hepatitis A) or in case of sexual intercourse unprotected, intravenous drug use, or even some care in areas of poor hygiene (hepatitis B).
The symptoms of jaundice
Aside from its aesthetic consequences, the change of color of the integuments (skin and mucous membranes) has no pathological consequence. Depending on the causes of jaundice, other signs may be associated, allowing to guide the possible diagnosis: abdominal pain, fever, itching, fatigue, joint pain, etc.
Free bilirubin, so not yet “conjugated” in the liver, is toxic to the brain. In the newborn, too much accumulation can be particularly harmful for the brain and require urgent treatment.
What are the causes ?
Apart from the toxicity of free bilirubin for the brain (neurotoxicity), in the vast majority of cases, the causes of jaundice condition the prognosis, benign or serious depending on the case. Similarly, the treatment differs according to the origin of the jaundice. The exact diagnosis is therefore indispensable. To make this diagnosis, doctors use first-line, clinical examination, a blood test and ultrasound of the abdomen. Other explorations may then be necessary: CT scan, MRI, cholangiography, endoscopy, biopsy, etc.
Jaundice is a symptom and not a disease, it is not contagious.
Schematically, there are two different kinds of jaundice:
- It may be an increased production of free bilirubin
- Or it may be conjugated bilirubin.
In the first case, during an increase in free bilirubin, the excess may be related to an increased destruction of red blood cells (hemolysis) or a bad conjugation of bilirubin in the liver. The first situation often causes anemia (lowering of hemoglobin) and may suggest a blood disease, or an infection, a drug cause, an immunological disorder, etc.
In the case of jaundice by increased bilirubin conjugate, jaundice is most often related to a genetic disease (Gilbert’s disease) causing a lack of conjugation of bilirubin. This Gilbert’s disease or Gilbert’s syndrome is benign in the vast majority of cases.
In the second case, when there is an excess of conjugated bilirubin, there is increased elimination in the urine which takes a darker color associated with stool discoloration. Two types of causes can be suspected. In the first place, liver damage (hepatitis, cirrhosis, parasitosis, etc.) or an obstacle on the bile ducts that prevents the elimination of bilirubin. In this last case, we mainly look for a calculation, blocking the passage, a local tumor compressing the bile ducts … Other rarer hepatobiliary causes can also be responsible for jaundice.
The particular case of jaundice in the baby
In newly born children, there are several causes of jaundice that are specific to this period of life.
The liver is sometimes not mature enough to conjugate bilirubin. But the latter increases greatly because the newborn must “exchange” its fetal hemoglobin for an adult form, which causes the destruction of many red blood cells in a very short time, a phenomenon that can be the cause of jaundice.
Jaundice in breast milk can also be seen in breastfed infants.
A blood incompatibility between the fetus and its mother can be responsible for a destruction of red blood cells and thus a strong accumulation of bilirubin. This is the case when the mother is Rh negative and her child is Rh positive. The mother then immunizes against the Rh factor of her fetus and makes antibodies that pass through the placenta to destroy the baby’s red blood cells. As long as the child is not born, bilirubin is removed by the placenta, but after delivery, its accumulation causes jaundice.
Apart from other causes related to congenital diseases, significant hematomas that can occur during delivery can also release a lot of hemoglobin and ultimately bilirubin.
The treatments of jaundice
Prevention of jaundice is not possible in all cases. Nevertheless, precautions can limit certain causes.
The following measures can prevent the occurrence of diseases that could lead to jaundice:
- Moderate moderate alcohol consumption,
- To vaccinate against hepatitis B or A,
- Having safe sex,
- Respect hygiene rules in countries at risk of infectious transmission via food
- Avoid periods of fasting or dehydration if you have Gilbert’s syndrome.
The treatment of jaundice is that of its cause:
- Sometimes, no care is needed: this is the case in Gilbert’s hereditary disease, which can cause jaundice outbreaks usually not serious, especially after a period of fasting or dehydration.
- In other situations, the resolution of the cause causes that of jaundice (hepatitis, resorption of hematomas, …).
- In jaundice with mother’s milk, heating at 60 ° C, or switching to artificial milk, usually resolves the situation.
- In “physiological” jaundice of the newborn, exposure to blue light facilitates the elimination of bilirubin. Sometimes this measure is insufficient and, given the neurological risk, it is necessary to perform an exchange transfusion (we change all the blood of the baby that is replaced with a transfusion). – In other cases, it is a surgical intervention that is required (stones, tumors), or the administration of specific drugs (infections, blood diseases, cancer).