Herpes Zoster Infection as a Presentation for Hidden Diabetes Mellitus

The incidence of undiagnosed diabetes mellitus (DM) is high among patients with herpes zoster (HZ) due to complex immune defects. The DM and HZ affect each other's course aggressively. We introduced three cases of HZ for two men and one woman who were nondiabetic at presentation. Later on, their treating physicians diagnosed them with DM with different degrees of severity of hyperglycemia. They referred the three patients to us for a second opinion and for managing their DM in the presence of HZ. We managed them according to their glycemic figures. The patients were asymptomatic at different follow-up visits. The innate immune responses are lower in patients with DM, which is not enough for cutaneous protection during the reactivation of the dormant varicella-zoster virus (VZV). HZ and post-herpetic neuralgia (PHN) show an aggressive course in patients with DM and reduce the patient's quality of life. We illustrated three quiescent risk factors for our patients, in addition to undiagnosed DM, prior statin use, and comorbidity with coronary artery disease (CAD) and thyroid disease. These risk factors might affect the immunomodulatory responses and proinflammatory cytokines in various degrees. The management of patients with HZ and underlying DM is challenging. The therapy relies on antiviral medications for infection control, pain control, and a specific management plan for DM in which premixed insulin and metformin are the main components. Nondiabetic patients with acute HZ infection, whatever the severity, need to be screened for diabetes and/or hyperglycemia at the baseline interview and on frequent intervals thereafter to diagnose possible underlying DM.