Serious infection risk in children with psoriasis on systemic treatment: A propensity score-matched population-based study

Background: Psoriasis is increasingly treated with systemic medications, yet their safety is not well characterized in children. Objective: We sought to estimate the 6-month risk of serious infections in children with psoriasis treated with biologics, systemic nonbiologics, and phototherapy. Methods: Using insurance claims data, we identified children aged <18 years with psoriasis and compared the frequency of serious infections in those initiating biologics, systemic nonbiologics, and phototherapy. Relative risks were estimated before and after 1:1 propensity score matching. Results: Among 57,323 children with psoriasis, the 6-month risk of infection was 4.2 per 1000 patient-years in 722 biologic initiators, 5.1 in 988 systemic nonbiologic initiators, and 1.1 in 2657 phototherapy initiators. The relative risk (95% confidence interval) of infection in biologics vs nonbiologics was 0.67 (0.11-3.98), in biologics vs phototherapy was 1.50 (0.25-8.95), and in nonbiologics vs phototherapy was 5.00 (0.59-42.71). The background risk of infection in children with psoriasis was 1 per 1000, almost double the risk compared with children without psoriasis (relative risk, 1.84; 95% confidence interval, 1.15-1.97). Conclusions: We found no meaningful difference in infection risk between biologics vs nonbiologics and no robust difference between systemic users vs phototherapy. Independent of treatment, children with psoriasis had a higher risk of infection than those without psoriasis.