“…17 In an extensive search of the literature, only two studies dealing with the incidence of HZ related to biologic drugs among psoriasis patients Herpes zoster, psoriasis and biologics drugs (both limited to treatment with efalizumab) were found. 18,19 Previous studies of the association between biologic drugs and HZ have included patients with rheumatoid arthritis, 12,13,20-23 inflammatory bowel disease 24 or some combination of these diagnoses. 25,26 Langley et al 18 reported that among 2475 patients treated with efalizumab for psoriasis, less than 2% developed HZ.…”