Cholestasis is seen with many hepatobiliary disorders which produce extrahepatic biliary obstruction and/or intrahepatic biliary disruption. One particularly troublesome symptom associated with cholestasis is pruritus, which can range in severity from mild, to moderate in which sleep is disturbed, to extreme in which the lifestyle of the patient is completely disrupted.
The pathogenesis of pruritus in cholestasis is unknown but several hypotheses have been proposed, including bile acid accumulation and increased opioidergic tone .
Bile acids — One theory proposed that elevated levels of bile acid in the skin of patients with cholestatic diseases act as pruritogens. Observations in favor of this theory include the recovery of bile acids from the skin surface of affected patients in relation to the intensity of pruritus , although the reliability of the methods used is uncertain. Other studies showed the ability of administered bile acids to induce pruritus [3,4]. There are, however, three observations that are not consistent with a primary role for bile acids as the cause of pruritus:
●The occasional subsidence of pruritus despite ongoing cholestasis and persistence of elevated plasma bile acid levels .
●The absence of pruritus in many patients with cholestasis and elevated plasma bile acid levels .