COVID-19 and herpes zoster co-infection presenting with trigeminal neuropathy.

BACKGROUND: Varicella-zoster virus (VZV) is a human neurotropic virus that remains in a latent state within ganglionic neurons throughout the entire neuroaxis after the primary infection. When herpes zoster (HZ) leads to trigeminal involvement, the ophthalmic division is the most implicated. COVID-19 has emerged as a viral cause of severe acute respiratory syndrome that has spread all over the world in the last months. Co-infection with COVID-19 and other viruses has been reported, but sparsely, and involving the respiratory viruses. METHODS: The case of a co-infection of COVID-19 with VZV is reported, and the literature reviewed. RESULTS: A 39-year-old immunocompetent man presented with oligosymptomatic infection with COVID-19, which evolved to left facial HZ, affecting the three divisions of the trigeminal nerve. The co-infection was remotely registered, being the respiratory viruses, especially influenza, the most commonly cited association. However, the present case illustrates the emergence of a latent virus infection, which might be favored by the inflammatory response to the former agent (COVID-19). This reaction ascended from the nasal cavity, where trigeminal branches are also placed. CONCLUSIONS: The emergence of latent VZV infection in this rare presentation might illustrate an effect, at least locally, of COVID-19. This virus possibly induced a retrograde reactivation of VZV in a young immunocompetent patient.