ABSTRACT

Background:

For decades methotrexate has been used in the treatment of psoriasis with wellestablished efficacy. Although many theories regarding methotrexate’s mechanism of action in psoriasis were suggested, the exact the mechanism of action is still not very well understood. This paper reviews the published literature on methotrexate mechanism of action in psoriasis. Articles published with English abstracts between January 1970 and December 2008 identified in MEDLINE were reviewed. It is likely that methotrexate interferes with the inflammatory pathways critical to psoriasis pathogenesis by multiple mechanisms. Current evidence suggests that methotrexate, as an immunomodulatory agent and anti-metabolite, decreases T-cell-mediated inflammation at multiple steps and that explains its efficacy in treating various inflammatory diseases including psoriasis.