Incidence of herpes zoster infections in juvenile idiopathic arthritis patients

The risk of herpes zoster among patients with juvenile idiopathic arthritis (JIA) exposed to biologics has not been evaluated. We determined incidence rates of herpes zoster among children with JIA in correlation with medication at time of occurrence and total drug exposure. The German biologics register database was used to identify patients with herpes zoster. Crude infection rates and incidence ratios (IRR) were compared to published rates. Demographics and overall exposure and particular exposure time to corticosteroids, immunosuppressive drugs and biologics were analyzed. The JIA cohort included 3,042 patients with 5,557.9 person-years of follow-up; 1,628 have used corticosteroids, 2,930 methotrexate and 1,685 etanercept. In total, 17 herpes zoster events have been documented [6/1,000 patients (3.5–9.0); 3.1/1,000 patient-years (1.9–4.9)]. Thus, the incidence rate in JIA patients was higher than expected [IRR 2.9 (1.8–4.5), p