Inflammatory Bowel Disease and the Risk of Herpes Zoster.

To the Editor:

Recently, one cohort study conducted by Soh et al.1 published in Gut and Liver disclosed that inflammatory bowel disease (IBD)was associated with an elevated risk of herpes zoster (adjusted hazard ratio of 1.40 in ulcerative colitis and 2.13 in Crohn’s disease), which was consistent with the findings of previous studies.2,3 Some of my ideas are shared with the readers. First, the incidence of herpes zoster was higher in people with IBD than those without IBD in Soh et al.’s study (14.51 per 1,000 person-years vs 9.19 per 1,000 person-years). The attributable risk caused by IBD was 5.32 per 1,000 person-years.1 Therefore, lack of IBD may reduce the cases of herpes zoster by approximately 53 per 10,000 person-years of follow-up. Similarly, another cohort study disclosed that the incidence of herpes zoster was higher in people with chronic pancreatitis than those without chronic pancreatitis (6.22 per 1,000 person-years vs 4.63 per 1,000 person-years).4 Therefore, lack of chronic pancreatitis may reduce the cases of herpes zoster by approximately 16 per 10,000 person-years of follow-up. These results indicate that the impact of IBD on the risk of herpes zoster is higher than that of chronic pancreatitis. Second, alcohol consumption is a major cause of chronic pancreatitis. Once alcohol intake is stopped, the risk of chronic pancreatitis would potentially be decreased, and then the risk of herpes zoster would also be decreased. However, removing IBD is unlikely because IBD currently cannot be prevented or cured. Vaccinations for herpes zoster should be considered from the perspective of primary prevention. One meta-analysis disclosed that the risk of herpes zoster was significantly lower in people aged ≥60 years who received the live attenuated vaccine of varicella-zoster virus than those without vaccination (risk ratio, 0.49; 95% confidence interval, 0.43 to 0.56).5 Third, not all countries can afford the cost of a universal vaccination program for herpes zoster. Therefore, people who have risk factors for herpes zoster should be regarded as the first priority for receiving the herpes zoster vaccination. Soh et al.’s study highlights that people with IBD are at high risk for herpes zoster, and these people should receive vaccinations for herpes zoster.