Herpes Zoster in an Immunocompetent Child Following an Influenza-Like Illness

Herpes zoster (HZ) or shingles is uncommon in children and is traditionally associated with advancing age and immunocompromised states. However, HZ may also occur in immunocompetent children, in whom diagnosis may be overlooked due to its rarity and broad differential diagnosis of pediatric vesicular eruptions. We report the case of an immunocompetent 11-year-old boy with a previous history of natural varicella infection who presented to a primary care clinic with a painful unilateral vesicular rash over the T5-T6 dermatomes. The rash developed 1 week after an influenza-like illness following close contact with a classmate with laboratory-confirmed influenza. A clinical diagnosis of HZ was made based on the characteristic unilateral dermatomal distribution of the rash. The patient was treated with oral acyclovir on day 3 of the rashes onset and recovered completely within 1 week without complications such as secondary infections or postherpetic neuralgia. This case highlights that HZ should be considered in the differential diagnosis of a unilateral dermatomal vesicular rash in children, even in the absence of recognized risk factors such as immunodeficiency. The close temporal association with the preceding influenza-like illness raises the possibility that transient post-viral immune dysregulation may have contributed to the varicella zoster virus reactivation. Although the causality cannot be established from a single case, this observation generates hypothesis that warrants further investigation in future studies. Early clinical recognition and prompt antiviral therapy in the primary care setting may facilitate recovery and contribute to favorable clinical outcomes.