Cholestasis

The causes of cholestasis are divided into two groups: those originating within the liver and those originating outside the liver.

Jaundice Jaundice in Adults In jaundice, the skin and whites of the eyes look yellow. Jaundice occurs when there is too much bilirubin (a yellow pigment) in the blood—a condition called hyperbilirubinemia. (See also Overview... read more , dark urine, light-colored stools, and generalized itchiness are characteristic symptoms of cholestasis. Jaundice is a yellow color of the skin and eyes that results from excess bilirubin deposited in the skin, and dark urine results from excess bilirubin excreted by the kidneys. The skin itches, possibly because bile products accumulate in the skin. Scratching can damage the skin. Stools may become light-colored because the passage of bilirubin into the intestine is blocked, preventing it from being eliminated from the body in stool. Stools may contain too much fat (a condition called steatorrhea) because bile cannot enter the intestine to help digest fat in foods. Fatty stools may be foul-smelling.

The lack of bile in the intestine also means that calcium and vitamin D are poorly absorbed. If cholestasis persists, a deficiency of these nutrients can cause loss of bone tissue. Vitamin K, which is needed for blood clotting, is also poorly absorbed from the intestine, causing a tendency to bleed easily.

Prolonged jaundice due to cholestasis produces a muddy skin color and fatty yellow deposits in the skin. Whether people have other symptoms, such as abdominal pain, loss of appetite, vomiting, or fever, depends on the cause of cholestasis.

A doctor suspects cholestasis in people who have jaundice and tries to determine whether the cause is within or outside the liver on the basis of symptoms and the results of a physical examination.

Recent use of drugs that can cause cholestasis suggests a cause within the liver. Small spiderlike blood vessels visible in the skin (called spider angiomas), an enlarged spleen, and accumulation of fluid within the abdomen (ascites Ascites Ascites is the accumulation of protein-containing (ascitic) fluid within the abdomen. Many disorders can cause ascites, but the most common is high blood pressure in the veins that bring blood... read more )—which are signs of chronic liver disease—also suggest a cause within the liver.

Findings that suggest a cause outside the liver include certain kinds of abdominal pain (such as intermittent pain in the upper right side of the abdomen and sometimes also in the right shoulder) and an enlarged gallbladder (felt during the physical examination or detected by imaging studies).

Some symptoms (such as loss of appetite, nausea, and vomiting) do not indicate whether the cause is within or outside the liver.

Typically, blood tests are done to measure levels of two enzymes (alkaline phosphatase and gamma-glutamyl transpeptidase) that are very high in people with cholestasis. However, if the level of alkaline phosphatase is very high but the level of gamma-glutamyl transpeptidase is normal, the cause of the high level of alkaline phosphatase is probably not cholestasis. A blood test that measures the level of bilirubin indicates the severity of the cholestasis but not its cause.

An imaging study Imaging Tests of the Liver and Gallbladder Imaging tests of the liver, gallbladder, and biliary tract include ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI), endoscopic retrograde cholangiopancreatography... read more , usually ultrasonography, is almost always done if blood test results are abnormal. Computed tomography (CT) or sometimes magnetic resonance imaging (MRI) may be done in addition to or instead of ultrasonography. If the cause appears to be within the liver, a liver biopsy Biopsy of the Liver Doctors can obtain a sample of liver tissue during exploratory surgery, but more often they obtain a sample by inserting a hollow needle through the person's skin and into the liver. This type... read more may be done and usually establishes the diagnosis.

If the cause appears to be blockage of the bile ducts, more precise images of these ducts are usually needed. Typically, one of the following is done:

A blockage of the bile ducts can usually be treated with surgery or endoscopy (using a flexible viewing tube with surgical instruments attached).

A blockage within the liver may be treated in various ways depending on the cause. If a drug is the suspected cause, the doctor stops its use. If acute hepatitis is the cause, cholestasis and jaundice usually disappear when hepatitis has run its course. People with cholestasis are advised to avoid or stop using any substance that is toxic to the liver, such as alcohol and certain drugs.

Cholestyramine, taken by mouth, can be used to treat itchiness. This drug binds with certain bile products in the intestine, so they cannot be reabsorbed to irritate the skin.

Unless the liver is severely damaged, taking vitamin K can improve blood clotting.

Supplements of calcium and vitamin D are often taken if the cholestasis persists, but they are not very effective in preventing loss of bone tissue.