Abstract: 【Abstract】 Objective To compare the efficacy and safety of biologics versus methotrexate in the treatment of severe pediatric plaque psoriasis. Methods A retrospective matched case-control study was carried out. Twenty children with severe plaque psoriasis from Beijing Children′s Hospital, Capital Medical University from June 2016 to November 2021 were included in this study, and the patients treated with biologics （adalimumab or secukinumab） were matched with those treated with methotrexate at a ratio of 1∶1 according to the psoriasis area and severity index （PASI） score and age. PASI, physician′s global assessment （PGA）, and body surface area （BSA） scores were assessed at weeks 4, 8 and 12 after the start of treatment, and adverse drug reactions were recorded. Statistical analysis was mainly carried out by using Mann-Whitney U test, Fisher′s exact test and generalized estimating equations. Results At weeks 4 and 8, the proportions of patients achieving PASI75 and PASI90 were significantly higher in the biologics group （PASI75: 7/10, 10/10, PASI90: 5/10, 9/10, respectively） than in the methotrexate group （PASI75: 1/10, 5/10, PASI90: 0, 1/10, respectively; all P < 0.05）, while there was no significant difference between the biologics group and methotrexate group at week 12 （PASI75: 10/10 vs. 8/10, PASI90: 9/10 vs. 4/10, both P > 0.05）. There were no significant differences in the PASI, BSA or PGA scores between the two groups at baseline （all P > 0.05）, while the biologics group showed significantly decreased PASI and BSA scores at weeks 4, 8 and 12, and significantly decreased PGA score at week 8 compared with the methotrexate group （PASI: Z = 2.50, 3.56, 2.63, respectively; BSA: Z = 2.87, 3.57, 2.40, respectively; PGA: Z = 2.81; all P＜0.05）. Analysis of changes over time showed that the PASI, PGA and BSA scores in the biologics group significantly decreased at weeks 4, 8 and 12 compared with those at baseline （all P＜0.01）; the PASI and PGA scores significantly decreased at weeks 8 and 12 compared with the corresponding scores at week 4 （all P＜0.05）; however, there were no significant differences in the PASI, PGA or BSA scores between week 12 and 8 （all P＞0.05）. In the methotrexate group, the PASI, PGA and BSA scores at weeks 4, 8 and 12 were all significantly lower than the corresponding scores at the previous adjacent time points （all P＜0.05）. There was no significant difference in the incidence of adverse reactions between the two groups （P = 0.650）, and no serious adverse reactions occurred in either group. The main adverse reaction was infection in the biologics group, while infection and elevation of transaminase levels were common in the methotrexate group. Conclusion Biologics and methotrexate were both effective and safe for the treatment of severe pediatricplaque psoriasis, and biologics facilitated rapider achievement of PASI75 and PASI90 compared with methotrexate.

Key words: Psoriasis, Methotrexate, Biological agents, Child, Plaque psoriasis