Varicella Zoster Virus in Inflammatory Bowel Disease Patients: What Every Gastroenterologist Should Know

Abstract Primary varicella zoster virus [VZV] infection results in varicella [chickenpox] and its reactivation results in herpes zoster [HZ; shingles]. Patients with inflammatory bowel disease [IBD] are susceptible to complications of primary VZV infection and have an increased risk of HZ. Concerns of VZV and HZ infection in the IBD population have been highlighted by the emergence of JAK inhibitors and their safety profile in this patient population, as with tofacitinib for the treatment of ulcerative colitis [UC]. The current pipeline of emerging therapies includes novel molecules targeting multiple pathways, including JAK/signal transducer and cytokine signalling pathways, such as JAK/STAT. Hence VZV and HZ will be increasingly relevant for gastroenterologists treating IBD patients in light of these emerging therapies. This review will focus on the epidemiology, disease course, prevention, and management of these two distinct infections in patients with IBD.