A study was made of 67 severely psoriatic individuals, some of whom had received methotrexate therapy for periods varying from nine months to 14 years while others were untreated with methotrexate. Liver biopsy material from patients in both groups showed comparable histologic abnormalities regardless of treatment, including fatty changes, nuclear and mitochondrial alterations, fibrosis, and in a small percentage, frank cirrhosis. Inflammation and necrosis, however, were somewhat greater in the treated group. Minor differences in the results of liver function tests between the two groups were statistically unimportant. The concept that methotrexate therapy in psoriatics is responsible for extensive hepatic changes correlating with duration of therapy and dosage remained unsubstantiated.
Shapiro HA, Trowbridge JO, Lee JC, Maibach HI. Liver Disease in Psoriatics—An Effect of Methotrexate Therapy?. Arch Dermatol. 1974;110(4):547-551. doi:10.1001/archderm.1974.01630100007001