Complications in methotrexate treatment of psoriasis with particular reference to liver fibrosis.

All patients taking methotrexate for treatment of psoriasis over the past 5 yr have been reviewed. Thirty-eight patients have had pretreatment liver biopsies and at least 1 repeat liver biopsy. Of the 38, nine (24%) have developed significant liver fibrosis or cirrhosis, and have stopped treatment. The high incidence of fibrosis is attributed to synergism between methotrexate and other hepatotoxic factors, particularly alcohol, the use of a baseline biopsy to identify subsequent changes, and the early detection of fibrosis by sensitive histological techniques.