Because the liver cells are leaking.
The liver must produce bile and drain it into the intestines. Sometimes an obstacle appears in the path of bile, and it does not enter the intestines. Or the liver cells themselves cannot drain bile from themselves. All this called cholestasis. That is, stagnation of bile.
Sometimes with stagnation of bile there is an itching of the skin. With cholestasis of pregnant women, itching of the skin occurs in 100% of cases, but with cirrhosis of the liver - only in 7%.
Where it itches
Itching can be all over the body or only affects certain parts. Especially hitting the palms and soles.
Itching usually worsens at night or after stressful situations.
It gets easier in cooler weather.
The strangest thing is that no one knows for sure why itchy skin appears with cholestasis.
Bile acids
Bile contains bile acids. These are pretty caustic things. If bile enters the intestines without food, then it irritates the intestines so much that there will be diarrhea. It would be logical to assume that bile acids with stagnation of bile can be deposited in the skin and cause itching. But in this idea, something does not add up.
It has long been noticed that itching with cholestasis can by itself decrease or increase. And it does not depend on the level of bile acids in the blood.
Many patients with severe bile congestion never have itchy skin at all.
Some people literally tested the amount of bile acids in the skin of people with bile stasis and found no connection with itching.
Liver juice
There isn't really any liver juice, but the idea was that bile is like soap. It emulsifies the fat that we eat, and in much the same way it can act on the membranes of liver cells.
Well, that is, there is fat in the membranes of our cells, and bile acts on it like soap and washes away. As a result, the membranes of the liver cells begin to leak, and the leaked contents will be quite caustic, get into the bloodstream and cause itching somewhere.
There is still a lot of interesting things, but without a gastroenterologist you will not understand this topic. Excuse me!
