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 as-sessed methotrexate adverse events and effectivene-ss in paediatric patients with psoriasis in a real-world setting. Furthermore, gastrointestinal adverse events and methotrexate effectiveness were compared bet-ween folic acid regimens (5 mg once weekly vs 1 mg 6 times weekly). Data for paediatric patients with pso-riasis treated with methotrexate from September 2008 to October 2020 were extracted from Child-CAPTURE, a prospective, daily clinical practice registry. Effecti-veness was determined by Psoriasis Area and Severity Index (PASI). Comparison of persistent gastrointesti-nal 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 5 2.0 was achieved by ap-proximately 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 ac-hieved a PASI 5 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 methotrexa-te treatment without considerable side-effects during a 2-year follow-up.