Observation: All of the grouped vesicles appeared to be of uniform size.
Lab: A Tzanck smear was positive for multinucleated giant cells.
Diagnosis: Herpes zoster roughly C3 - 6.
Herpes zoster in children is unusual but not all that rare. There are a few cases of HZ after vaccination for varicella. As he felt well, and as the effect of specific antiviral therapy is not striking; after discussion with his mother it was elected to simply follow. In out opinion, in healthy children and young adults the course of HZ is usually relatively mild and almost never followed by post-herpetic neuralgia. Immunity seems to wear off over time and it appears that this attenuated vaccine is capable of causing H.Z. The other possibility is that this is zosteriform simplex. We did not culture for that.
While researching this case, we looked up "zosteriform simplex." An observation (ref 4) indicates that in these patients the vesicles are of uniform size (as we see here). This would tilt us towards a diagnosis of Zosteriform Herpes Simplex here, and not of vaccine failure. Should this child get a recurrence, that would clinch the diagnosis.
1. Herpes zoster in children.
Herpes zoster (HZ) in immunocompetent children is quite uncommon. Initial exposure to the varicella-zoster virus (VZV) may be from a wild-type or vaccine-related strain. Either strain may cause a latent infection and subsequent eruption of HZ. We present a case of HZ in a 15-month-old boy after receiving the varicella vaccination at 12 months of age. A review of the literature regarding the incidence, clinical characteristics, and diagnosis of HZ in children also is provided.
Vaccines are less effective among high-risk patients, as well as being more dangerous because they contain attenuated live virus. In a study performed on children with an impaired immune system, 30% had lost the antibody after five years, and 8% had already caught wild chickenpox in that five-year period.