The risk of herpes zoster during biological therapy for psoriasis and other inflammatory conditions

Recent advances in biological therapies have proved highly effective in treating psoriasis and other inflammatory conditions, including psoriatic arthritis, rheumatoid arthritis, inflammatory bowel disease and ankylosing spondylitis. However, adverse effects related to their immunosuppression have been observed, including an increased propensity to viral infections. This review evaluates the evidence of herpes zoster (HZ) risk from biologics based on clinical reports, cohort studies and randomized controlled studies. The risk of HZ associated with these agents remains controversial, especially when comparing their risk with non-biological therapy used to treat the same inflammatory conditions. This review specifically assesses the risk of the TNF inhibitors etanercept, adalimumab and infliximab, as well as interleukin-12/23 inhibitor ustekinumab. We found multiple cohort studies, randomized controlled trials and case reports that suggest infliximab increases risk of HZ, whereas adalimumab, etanercept and ustekinumab HZ risk remain controversial. Nevertheless, HZ vaccination should be considered prior to initiation of biological therapy, particularly infliximab.