No increased risk of sudden sensorineural hearing loss following recent herpes zoster: a nationwide population-based study

Conclusion: There is no increased risk for sudden sensorineural hearing loss (SSNHL) among people who have experienced a recent herpes zoster attack, compared with a matching population.
Objective: The pathogenesis of SSNHL remains unknown, but viral infection is considered to be one of the main causes. The objective of this case-cohort study was to investigate the frequency and risk for SSNHL following a recent herpes zoster attack in the general population.
Methods: We extracted 313 612 patients with herpes zoster from a nationwide health registry in Taiwan, and also randomly selected 313 612 matched control subjects. Each participant was individually tracked for 2 months from their index ambulatory care visit to identify those who developed SSNHL. Stratified Cox proportional hazard regressions were conducted to analyze the risk of SSNHL for the sampled patients.
Results: Of the sample of 627 224 patients, 121 (0.02%) had SSNHL during the 2-month follow-up period, 59 from the study group (0.02% of the herpes zoster patients) and 62 from the comparison group (0.02% of patients without herpes zoster). Regression analysis revealed no increased adjusted hazard of SSNHL during the 2-month follow-up period for patients with herpes zoster as compared to those without (hazard ratio = 0.89, 95% confidence interval (CI) = 0.63-1.28, p = 0.540).