Most systemic psoriasis treatments carry similar risks of serious infection, long-term registry data suggest, although risankizumab is associated with a lower risk than some comparators in recurrent-event analyses.

Systemic therapies for psoriasis alter immune function and may increase susceptibility to serious infection, but long-term comparative safety data for newer biologics are limited.

To address this, a large-cohort analysis of data from the British Association of Dermatologists Biologic and Immunomodulators Register (BADBIR) examined the risk of serious infection across both established and newer systemic psoriasis therapies.

Published in the British Journal of Dermatology, 46,770 treatment episodes among 18,976 adults with dermatologist-confirmed moderate-to-severe psoriasis enrolled in BADBIR between 2007 and 2025 were included.

Patients had at least six months of follow-up and received either standard systemic therapies, including methotrexate, ciclosporin and acitretin, or targeted therapies. These included biologics such as TNF-ɑ inhibitors adalimumab and etanercept, the interleukin (IL)-12/23 inhibitor ustekinumab, IL-17 inhibitors bimekizumab, brodalumab, ixekizumab and secukinumab, IL-23 inhibitors guselkumab, risankizumab and tildrakizumab, and the phosphodiesterase 4 inhibitor apremilast.

Serious infection was defined as infection requiring hospitalisation, intravenous antimicrobials or resulting in death during treatment or within 90 days of discontinuation.

Serious infection risk and psoriasis therapies

The primary analyses assessed both time-to-first serious infection and recurrent serious infection events after systemic psoriasis treatment. Overall, 3,210 first serious infections and 4,969 recurrent infection events were recorded across 129,696 patient-years of follow-up.

The overall incidence rate for the first serious infection was 27.67 per 1,000 person-years (95% CI 26.72–28.65). Among patients with a prior serious infection, the recurrent infection rate was 78.70 per 1,000 person-years (95% CI 75.17–82.36).

Using conventional time-to-first-event analysis, apremilast and secukinumab appeared to be associated with an increased risk of serious infection compared with adalimumab. However, these findings were inconsistent across sensitivity analyses and were observed only at isolated time points.

By contrast, recurrent event analysis, which incorporated multiple infections per patient and longer-term follow-up, demonstrated largely comparable infection risks across most therapies.

Risankizumab was associated with a lower risk of serious infection compared with brodalumab (HR 0.74; 95% CI 0.55–0.99), etanercept (HR 0.75; 95% CI 0.60–0.94) and standard systemic therapies (HR 0.80; 95% CI 0.65–0.98).

Respiratory infections dominate serious adverse events

Respiratory tract infections were the most commonly reported serious infections associated with systemic psoriasis treatment (26.1%), followed by urinary tract infections (10.5%), gastrointestinal infections (10.5%), bloodstream infections (9.1%) and skin infections (5.3%).

Serious infection-associated deaths were uncommon, with a rate of 1.81 per 1,000 person-years.

Prescribing decisions following serious infection were also examined. After an infection, 67.8% of patients continued the same therapy, while 18.2% discontinued treatment, 10.0% switched therapy and 4.0% postponed treatment.

Switching to IL-23 inhibitors and apremilast increased after infection episodes.

Limitations of the analyses included potential residual confounding inherent in observational cohort studies, missing baseline data for variables such as body mass index and smoking status, and limited sample sizes for some newer agents such as bimekizumab.

The authors concluded that treatment decisions should mainly be guided by patient characteristics and disease factors. Risankizumab may be considered a potential option for individuals worried about serious infections, but infection risk alone should not dictate therapy choice, they said.

Reference
Bright HRB et al. Serious infection risk with systemic treatments for psoriasis: a cohort study from the British Association of Dermatologists Biologic Interventions Register (BADBIR). Br J Dermatol 2026;doi:10.1093/bjd/ljag174.