Real-world Methotrexate Use in a Prospective Cohort of Paediatric Patients with Plaque Psoriasis: Effectiveness, Adverse Events and Folic Acid Regimen

In paediatric psoriasis, few studies have evaluated methotrexate effectiveness, adverse events and folic acid regimen. Therefore this study prospectively assessed methotrexate adverse events and effectiveness in paediatric patients with psoriasis in a real-world setting. Furthermore, gastrointestinal adverse events and methotrexate effectiveness were compared between folic acid regimens (5 mg once weekly vs 1 mg 6 times weekly). Data for paediatric patients with psoriasis treated with methotrexate from September 2008 to October 2020 were extracted from Child-CAPTURE, a prospective, daily clinical practice registry. Effectiveness was determined by Psoriasis Area and Severity Index (PASI). Comparison of persistent gastrointestinal adverse events between folic acid regimens were assessed through Kaplan–Meier analysis. A total of 105 paediatric patients with plaque psoriasis (41.0% male, mean age 14.1 years) were included. At week 24 and 48, an absolute PASI ≤ 2.0 was achieved by approximately one-third of all patients. During follow-up, 46.7% reported ≥ 1 persistent adverse events. After 1 and 2 years, approximately one-quarter of patients achieved a PASI ≤ 2.0 without persistent adverse events. Although non-significant, a possible trend towards lower occurrence of gastrointestinal adverse events was found for folic acid 1 mg 6 times weekly (p = 0.196), with similar effectiveness between folic acid regimens. These findings show that a subgroup of paediatric patients with psoriasis responded well to methotrexate treatment without considerable side-effects during a 2-year follow-up.