Successful Treatment of Topical 1% Methotrexate Gel in a Filipino Male With Moderate Plaque-type Psoriasis: A Case Report

Methotrexate (MTX) has been popular due to its availability and cost-effectiveness; however, it has known end-organ toxicity and teratogenicity, which limits its usage. Studies on topical MTX in other vehicle bases have varying reports in terms of treating psoriasis vulgaris. They have been studied in response to avoid the use of systemic MTX. To the authors’ knowledge, this is the first reported case of the use of topical MTX in a gel vehicle and its successful treatment of psoriasis vulgaris in a Filipino patient. A 37-year-old Filipino male patient with clinically diagnosed psoriasis vulgaris, body surface area (BSA) = 26% was evaluated after baseline laboratory evaluation, and was planned to start with oral MTX, but had expressed not to be treated with systemic medications. The authors decided that since topical corticosteroids on a large BSA would be detrimental and costly for the patient, he was started on formulated topical 1% MTX gel, which was applied for 6 weeks. BSA and Psoriasis Area and Severity Index (PASI) scores were assessed at two-week intervals for a total of eight weeks. Blood chemistry parameters, whole abdomen ultrasound and adverse drug reactions while on treatment and after eight weeks were monitored as secondary outcome measures. The patient noted a 10.1% improvement in the PASI score at the end of the application period of six weeks. The patient had normal blood chemistry parameters and whole abdomen ultrasound results at the start and at week eight of the study. No adverse drug reactions were also noted in the patient. Eight weeks after the start of the application of MTX, there was continuous improvement from the baseline. Topical MTX gel is a therapeutic option for mild to moderate plaque-type psoriasis due to its cost-effectiveness and without the unfavorable adverse effects of MTX in systemic form. Keywords: Case reports, methotrexate, psoriasis