Previous studies have shown increased risk of herpes zoster (HZ) infection in patients with inflammatory bowel disease (IBD). The aim of this study is to better characterize this possible association by conducting a meta-analysis. A comprehensive search of relevant literature until April 30, 2019, was performed. Data on HZ infection and medications in patients with IBD and controls were extracted. The relative risk (RR) and 95% confidence interval (CI) were calculated. Subgroup analyses were performed to assess the source of heterogeneity. Seven cohort studies were included that involved more than 1,000,000 participants. The RR of HZ infection in patients with Crohn's disease (CD) compared with non-CD patients was 1.74 (95% CI 1.57-1.92, p < 0.001). The pooled RR of HZ infection in patients with ulcerative colitis (UC) compared with non-UC was 1.40 (95% CI 1.31-1.50, p < 0.001). Subgroup analyses revealed that age, race, and publication year contribute to heterogeneity. We also found that steroid users were at increased risk of HZ in CD (OR = 1.78, 95% CI 1.10-2.88). Steroid users and anti-TNFα users were at increased risk of HZ in UC, with RRs of 1.99 (95% CI 1.64-2.42) and 2.29 (95% CI 1.52-3.45), respectively. Begg's test and Egger's test suggested no publication bias. There was a 74% increased risk of HZ infection in patients with CD and 40% increased risk of HZ infection in patients with UC compared with that in non-IBD. IBD patients with high risk of HZ infection may benefit from an HZ vaccine.
Keywords: Herpes zoster; Inflammatory bowel disease; Meta-analysis.