Incidence of herpes zoster in patients with inflammatory bowel disease.

BACKGROUND:Herpes zoster (HZ) is a prevalent disease caused by the reactivation of the varicella-zoster virus (VZV) and associated with chronic morbidity, particularly with post-herpetic neuralgia (PHN). Inflammatory bowel disease (IBD) has been associated with an increased risk of HZ, mainly when immunosuppressive treatment (IMT) is used. However, studies assessing the risk of HZ in IBD are scarce. AIMS:To evaluate the incidence rate and risk factors of HZ in IBD. METHODS:Retrospective study in IBD patients with a positive VVZ serology from two referral hospitals from the area of Barcelona. Diagnosis of HZ and its clinical features were recorded. RESULTS:A total of 398 IBD patients with a positive IgG-VVZ serology were identified. Fifty-eight percent of the patients received IMT (46.5% immunosuppressants monotherapy, 20.6% biologics monotherapy and, 32.7% combination therapy). After a median follow-up of 71 months (IQR 41.5-138.0), 17 (4.3%) patients developed HZ (cumulative incidence of 5.2 per 1000 person-year), 12 of them (70.6%) while receiving IMT. Median age at HZ episode was 38 years (IQR 27.5-52.5). Two (11%) developed PHN. Biological therapy was the only risk factor for developing HZ (OR 3.8 IC 95% 1.3-11.5; p=0.018). CONCLUSIONS:HZ is quite prevalent in IBD, occurring at early ages and particularly among patients using IMT. NPH appears to occur in a notable proportion of cases.