[Herpes Zoster Ophthalmicus presenting as acute headache].

Unlabelled: Herpes Zoster (HZ) is rare in childhood and is defined as the reactivation of the latent varicella-zoster virus in patients who have previously been infected with varicella. When the virus affects the ophthal mic nerve it is called herpes zoster ophthalmicus (HZO) and it can produce, among other symptoms, acute headache, so it must be considered as a differential diagnosis.

Objective: To describe a clinical case of HZO in a pediatric patient and to recognize its clinical manifestations and their importance in the differential diagnosis of acute headache in children.

Clinical Case: Immunocompetent 11-year- old girl, vaccinated according to the recommended immunization schedule, excluding chickenpox vaccine due to past infection, presented to the emergency department (ED) with a 5-day long uni lateral headache. After 36 hours of hospitalization, she presented vesicular cutaneous lesions in her forehead, left upper eyelid, and nose. Positive fluorescein stain dendritic corneal lesions were iden tified in the ophthalmic exam. Antiviral systemic and topic therapy were set, obtaining an initial good response, but later she presented complications such as postherpetic neuralgia one month after hospital discharge and several postherpetic neuralgia episodes despite treatment with gabapentin in addition to two herpes zoster ophthalmicus relapses with acute keratouveitis one year after the initial episode.

Conclusion: It is essential to include HZO in the differential diagnosis of acute headache, especially when presented unilaterally and/or with ocular symptoms, regardless of the presence of cutaneous lesions, and even more so in patients with history of chickenpox infection. Those patients who were vaccinated against this disease in their childhood will benefit from at least partial protection against HZO.