Information regarding the safety of biological drugs prescribed to psoriasis patients on daily and long-term bases is insufficient. We used data from the BIOBADADERM registry (Spanish Registry of Adverse Events for Biological Therapy in Dermatological Diseases) to generate crude rates of infection during therapy with systemic drugs, including biological drugs (infliximab, etanercept, adalimumab, and ustekinumab) and nonbiological drugs (acitretin, cyclosporine, and methotrexate). We also calculated unadjusted and adjusted risk ratios (RRs) (with propensity score adjustment) of infection, serious infections, and recurrent infections of systemic therapies compared with methotrexate, using Poisson regression. Our study included records of 2,153 patients (7,867.5 person-years). The adjusted RR of overall infection was significantly increased in the groups treated with adalimumab with methotrexate (adjusted RR = 2.13, 95% confidence interval [CI] = 1.2-3.7), infliximab (adjusted RR = 1.71, 95% CI = 1.1-2.65), cyclosporine (adjusted RR = 1.58, 95% CI = 1.17-2.15), ustekinumab with methotrexate (adjusted RR = 1.56, 95% CI = 1.08-2.25), and etanercept (adjusted RR = 1.34, 95% CI: 1.02-1.76) compared with methotrexate alone. Cyclosporine had a significant risk of serious infection (adjusted RR = 3.12, 95% CI = 1.1-8.8), followed by adalimumab combined with methotrexate (adjusted RR = 3.28, 95% CI = 0.8-13.5). Adalimumab in combination with methotrexate had the highest risk of infection recurrence (adjusted RR = 4.33, 95% CI = 2.27-8.24).

Patients receiving biologics had lower risk of AE. We did not find differences in the risk of serious or fatal AE.

Serious adverse events are more common in elderly patients, although they may be related to other variants that are associated with this age group and not due to the treatment itself. Use of biologics was associated with lower risk of adverse events in the whole group. We found no differences in this association between young and elderly. These results are reassuring, although uncontrolled confounding could not be excluded as an explanation for these findings, and the power of the study to detect differences was low.

Off-label doses of biologic agents for psoriasis are frequent in clinical practice. This information is especially relevant for pharmacoeconomic models.

Biologic therapies are associated with a lower rate of discontinuation-related AEs than are classic therapies in real clinical practice. Ustekinumab showed the lowest incidence.