Background: Herpes simplex virus 1 and 2 (HSV-1 and HSV-2) and varicella zoster virus (VZV) are neurotropic herpesviruses that cause vesicular mucocutaneous eruptions. They both establish latency in peripheral ganglia and can reactivate to cause episodic outbreaks. HSV occurs more often in the young and may reactivate frequently. VZV reactivation is associated with advancing age due to a decline in the VZV-specific T cell population. While both viruses have been isolated from the same sensory ganglia, they rarely cause simultaneous disease. In most of these cases, the viruses have been isolated at different body sites in immunocompromised hosts. However, clinical disease with concurrent detection of both HSV and VZV from the same anatomic location has been described. In a prior study of dual positive specimens, a lower PCR cycle threshold (Ct) was consistently observed for VZV, suggesting that zoster caused subsequent reactivation of HSV. Case presentation: Here we describe the case of a 64-year-old patient with uncontrolled diabetes who presented with painful penile ulcers and a dermatomal, crusted, left lower abdominal rash. His penile ulcers were positive for both HSV-2 and VZV by PCR. Ct data suggested that primary zoster led to secondary genital HSV-2. Hyperglycemia is known to cause reversible T cell dysfunction and was the likely precipitating factor for the patient's illness, which responded to oral valacyclovir. Conclusion: To our knowledge, this is the first report of diabetes-related concurrent herpesvirus reactivation. Clinicians should consider the possibility of simultaneous HSV and VZV infection in patients who present with dermatomal zosteriform lesions since higher antiviral doses are recommended for herpes zoster as compared to herpes simplex.

Keywords: zoster, herpes simplex, coinfection, virus activation, diabetes mellitus, hyperglycemia, case report