The clinical course of varicella and herpes zoster in children with inflammatory bowel disease – a prospective study

Introduction
Children with inflammatory bowel disease (IBD), particularly those treated with immunosuppressive drugs, are a risk group for severe, complicated and even fatal course of varicella-zoster virus (VZV) infection. The study aimed to analyse the clinical course, therapeutic approach and outcome of varicella and herpes zoster (HZ) in paediatric patients with IBD.

Material and methods
A prospective multicentre study including children with IBD and diagnosis of varicella or HZ was conducted September 2015 – June 2019. In all patients, a diagnosis of VZV infection was made on the basis of the characteristic rash.

Results
We identified 26 patients, including 14 with Crohn’s disease and 12 with ulcerative colitis. Twelve patients were diagnosed with varicella and 14 with HZ. No patient was immunized with varicella vaccine; no patient with varicella after known direct exposure received varicella zoster immunoglobulin. The median interval between diagnosis of IBD and diagnosis of VZV infection was 2 years and 10 months. Twenty patients were treated with immunosuppressive drugs, including thiopurine, an anti-tumour necrosis factor agent, mycophenolate mofetil, methotrexate and prednisone. Eight children were hospitalized in the course of VZV infection. Anti-viral treatment with acyclovir was used in 8/12 patients with varicella and 12/14 patients with HZ. Complications were diagnosed in 2 patients with varicella who were also receiving immunosuppressive therapy (both developed superficial bacterial infection). No complications were observed in patients with HZ. Neither dissemination to other organs nor fatal outcome was reported. Exacerbation of IBD was observed in 4 patients.

Conclusions
The clinical course of VZV infection in children with IBD is variable. Severe clinical course and complications seem to be rare. On the other hand, both varicella and HZ can be a risk of exacerbation of IBD.