Acute retinal necrosis secondary to multidrug-resistant herpes simplex virus 2 in an immunocompetent adolescent.

Purpose: To report the clinical course of a patient with acute retinal necrosis resulting from a multidrug-resistant strain of herpes simplex virus 2.
Methods: Observational case report.
Results: A 17-year-old man with no identifiable immune deficiency presented with pain and decreased vision in his left eye. He had dense anterior and posterior segment inflammation with retinal whitening suggestive of acute retinal necrosis, which progressed despite treatment with intravenous acyclovir, methylprednisolone, and ganciclovir. A transition to intravitreal and intravenous foscarnet led to clinical improvement. Genetic analysis revealed the etiology to be a multidrug-resistant strain of herpes simplex virus 2.
Conclusion: Antiviral resistance is an uncommon finding among viruses causing acute retinal necrosis in immunocompetent patients. Patients with these infections may be adequately treated with prompt recognition and a change in therapy to alternative antiviral agents such as foscarnet.