Comprehensive Literature Review Evaluating the Use, Safety, and Efficacy of Subcutaneous Methotrexate in the Treatment of Adult Patients With Moderate-To-Severe Plaque-Type Psoriasis.

Methotrexate (MTX) is a conventional systemic therapy widely used to treat chronic plaque-type psoriasis, a chronic inflammatory skin disease that significantly impacts patients' quality of life. MTX can be administered orally or subcutaneously. Over the past decades, the use of subcutaneous versus oral MTX has been a subject of ongoing debate among dermatologists. Therefore, this literature review aimed to investigate the differences between oral and subcutaneous MTX described in the scientific literature in terms of intestinal absorption and bioavailability, efficacy, safety, patient satisfaction and quality of life, treatment adherence, and economic outlook. Thirty-two articles were included in the review, notably including evidence-based guidelines on the management of psoriasis, as well as randomized clinical trials and real-world studies. Only European guidelines recommend the use of subcutaneous MTX over oral MTX; hence, the use of subcutaneous MTX is reported almost exclusively in European countries. Despite the paucity and heterogeneity of the literature, findings from the review suggest that subcutaneous MTX may overcome some limitations of the oral route in terms of intestinal absorption, bioavailability, and safety. Moreover, subcutaneous MTX may provide higher efficacy with a faster, or even greater, response in psoriatic patients and better adherence to treatment. In conclusion, subcutaneous MTX tends to be advantageous with regard to psoriasis management, similar to other chronic inflammatory diseases like rheumatoid arthritis; however, this comes with a higher cost. The treatment of psoriasis using subcutaneous MTX deserves further study, especially in the biologics age.