Herpes zoster in the first year of life following postnatal exposure to varicella-zoster virus - Four case reports and a review of infantile herpes zoster

Background: Herpes zoster, a painful vesicular dermatomal eruption, is the result of reactivation of the varicellazoster virus (VZV) from infected sensory ganglia. Traditionally, it is considered to be a disease of adults, in contrast to primary infection with VZV, which tends to occur mainly in children. Observations: We report 4 cases of infantile herpes zoster in healthy immunocompetent children, all of whom were exposed to primary varicella infection within the first few months of life. A review of 62 cases from the literature reveals that postnatally acquired herpes zoster is less common than intrauterine infection (31% [n=19] vs 69% [n=43]) and that there is a 1.5:1 male predominance. All dermatomes are equally affected. Conclusions: Although uncommon, herpes zoster can develop in immunocompetent children as young as a few weeks of age and should be considered in the differential diagnosis of vesicular eruptions in infants. Most frequently, it is the result of intrauterine VZV infection, but it can be secondary to postnatal exposure to VZV at an early age.