2024 Volume 61 Issue 2 Pages 196-200
A 2-year-old boy with B-cell precursor acute lymphoblastic leukemia (BCP-ALL) developed herpes zoster from the right shoulder to the forearm during induction therapy. He had no history of varicella (chickenpox) and had received a single dose of live attenuated varicella vaccine at the age of 1year-1 month. He was diagnosed with herpes zoster caused by the varicella vaccine strain, as revealed from genetic analysis of the blister fluid in his right arm. He responded well to acyclovir therapy. The vaccine strain was more attenuated than the wild-type strain, and the amount of latent virus in the ganglia was low and decreased over time. However, children with compromised cell-mediated immunity due to chemotherapy or immunosuppressants may develop herpes zoster caused by the vaccine strain even relatively longer after varicella vaccination. Early treatment is important when herpes zoster is suspected to be caused by a varicella vaccine strain.
