Can oral intake of ursodeoxycholic acid cause skin hypersensitivity reactions?/nBackground: An othe

Fråga: Can oral intake of ursodeoxycholic acid cause skin hypersensitivity reactions? Background: An otherwise healthy 38-year-old woman with gall stones is planned for cholecystectomy within a few weeks. To reduce the load of gall stones, she has been taking ursodeoxycholic acid for a week (clinical trial). Today, the woman presented with a non-pruritic rash on the trunk and the face, as well as a slight headache and mild nausea. There were no signs of serious hypersensitivity or infection. The patient had no history of allergy, and she was not taking any other medication.

Sammanfattning: Skin hypersensitivity reactions to ursodeoxycholic acid are extremely rare. Drug withdrawal should be considered, as well as other possible causes of the skin manifestation.

Svar: Ursodeoxycholic acid (UDCA) has been used for dissolving gall stones and in the treatment of cholestatic disease, eg primary biliary cirrhosis (1, 2).

Skin hypersensitivity reactions to UDCA are very rare. In fact, we have not found any reports in the pharmacological literature (3), or in the Swedish Drug Information System (4). However, in the WHO-data base (5), 35 cases of rash and 15 cases of urticaria are listed, but the causality is unclear with no further clinical details.

As regards the UDCA stereoisomer chenodeoxycholic acid, a case of possible induction of atopic dermatitis (6), associated with elevated IgE-levels indicative of a hypersensitivity reaction was described. Here, topical corticosteroids were without effect, but withdrawal of chenodeoxycholic acid lead to a prompt recovery. Chenodeoxycholic acid is not an approved drug in Sweden.

It is difficult to speculate about a possible underlying mechanism of skin hypersensitivity to an endogenous compound such as UDCA. The constitutive level of UDCA in bile is less than 5 per cent, whereas chenodeoxycholic acid is a major component. However, this balance will shift completely during UDCA treatment; UDCA will then dominate among bile acids not only in bile but also in peripheral blood (2). The latter offers at least a theoretical possibility for UDCA to exert peripheral effects, for instance in the skin.

In the present case, the association between UDCA and the skin reaction is difficult to assess. Withdrawal of UDCA should be considered. We suggest this case be reported to the Swedish Adverse Drug Reaction Advisory Committee (SADRAC, form enclosed).