Background: Herpes Zoster (HZ) is the reactivation of latent varicella-zoster virus due to such risk factors as aging and immunosupression. Diabetes Mellitus (DM) causes immunosupression and can activate HZ. This study focuses on the relationship between Herpes Zoster and Diabetes Mellitus.

Materials and Methods: In this cross-sectional study 103 patients referred to the dermatology and infectious disease clinics with HZ (cases) and 142 with other diseases (control) were enrolled to the study. They had no history of DM. Both groups were matched for age, gender and family history of DM. FBS was checked for all participants and FBS ³ 126mg/dl was defined as DM.

Results: 35.9% of patients with HZ and 19.7% of control group had DM. There was a significant relationship between HZ and undiagnosed DM (OR=2.28, 95% CI: 1.28-4.06, p=0.0046). On the other hand, DM was 2.28 times more common in HZ patients than in normal population.

Conclusion: Undiagnosed DM can cause HZ so the patients suffering from HZ but have no history of DM should be monitored for diabetes.