Varicella zoster exposure in IBD patients: rethink the rash decision.

The timely and updated ECCO consensus guidance on opportunistic infections in the context of IBD will be widely welcomed.1 With reference to Varicella zoster virus (VZV) infection, ECCO still recommends using patient reported exposure history as an indicator of immunity and VZV IgG testing and immunization in those without a clear exposure or vaccination history. The significantly higher risk of VZV infection in IBD patients, recognized from clinical trial data, bolstered by recent “real world” data and reports of severe, disseminated and occasionally fatal infection provide compelling reasons for a considered approach with a VZV history, raising debate on the appropriateness of patient-reported history alone as a measure of seroprotection.2 There have been a number of case reports of primary infection and a fatality among patients reporting primary infection but VZV IgG negative on testing.3 Kopylov and colleagues recently reported their experience in 121 IBD patients (87% on immunomodulators with Anti-TNF exposure in 71%) and noted that of 104 patients who recalled VZV exposure, 7 patients had negative or indeterminate VZV IgG.4 We recently reported our experience of accuracy of recall of VZV infection with corroborative serology.5 In a retrospective review of 220 IBD patients, data for VZV exposure and viral titres were available in 71 patients. Two-thirds were uncertain of prior VZV exposure. Although the overall prevalence of VZV IgG seropositivity was 87%, 10% were seronegative with a definite exposure history. These patients were on combined thiopurine and Anti-TNF immunosuppression.5 A total of 14%