Temporal Profile and Treatment of Purpureocillium lilacinum Keratitis Secondary to Herpes Zoster Reactivation Following Influenza Vaccination

PURPOSE: To report a temporal profile of Purpureocillium lilacinum keratitis (PLK) secondary to immune dysfunction induced by the combination of reactivation of herpes zoster dermatitis and recent influenza vaccination that suggests a possible association, including successful medical management. METHODS: A 64-year-old contact lens wearer presented with left eye keratitis days after receiving an influenza vaccination and subsequent development of herpes zoster lesions on the flank. Patient was initially treated for bacterial keratitis with fortified antibiotics and oral valacyclovir for her concurrent zoster. Pharmacotherapy was changed to topical voriconazole after cultures were positive for Purpureocillium lilacinum. Topography and anterior segment OCT demonstrated scarring at multiple levels within the cornea with irregular astigmatism. A literature review was conducted to identify mechanisms that demonstrate a temporal link between influenza vaccination, herpes zoster reactivation, and fungal keratitis. RESULTS: After the conclusion of topical therapy, the central corneal infiltrate regressed and a partial light-blocking anterior stromal scar remained. Best corrected visual acuity improved from 20/400 to 20/25. CONCLUSION: Transient systemic immune dysregulation, secondary to influenza vaccination and reactivation of systemic herpetic disease, compounded by contact lens wear, may create a favorable environment for opportunistic fungal keratitis. This case highlights the importance of adequately assessing and treating for existing comorbidities in the successful treatment of mycotic keratitis.