Double Trouble: An Unusual Keratitis Case of Herpes Simplex Virus and Varicella-Zoster Virus Co-infection

The aim of this study was to describe a case of herpes simplex virus (HSV) and varicella-zoster virus (VZV) corneal co-infection in a patient with systemic immunosuppression.

A 77-year-old White man who was recently administered pembrolizumab present with reduction in visual acuity in his left eye from 20/25 to 20/50. There was a known history of ocular HSV keratitis. Slit-lamp examination showed superficial dendritic lesions suggestive of VZV.

Viral polymerase chain reaction testing was positive for both HSV and VZV, confirming clinical diagnosis of VZV keratitis in the setting of recurrent HSV keratitis. The infection responded to treatment with topical trifluridine. Two months later, he had another episode of keratitis based on his symptoms reported through telephone encounter which resolved with trifluridine. Unfortunately, the patient committed suicide 4 months after onset.

This is the first case of keratitis with HSV and VZV co-infection likely related to systemic immunosuppression. Clinicians should have a high suspicion for viral co-infections in the setting of systemic immunosuppression.