Balanitis is a risk factor for herpes zoster.

Both balanitis and herpes zoster (HZ) may be influenced by the immune system. The objective of this study was to investigate the association between balanitis and HZ. We selected patients aged 20 years and older who were newly diagnosed with balanitis from 2000 to 2010 through the Longitudinal Health Insurance Database 2000. The non-balanitis cohort consisted of randomly selected patients who were matched to the balanitis cohort by age. Distributions of age and comorbidities were compared between the balanitis and non-balanitis cohorts; the categorical variables were examined using a Chi-squared test and the continuous variables were examined using a t-test. Univariable and multivariable Cox proportional hazards regression models were used to estimate the hazard ratios and 95 % confidence intervals for HZ among the balanitis patients in relation to the non-balanitis patients. We identified 4,028 patients with balanitis who were matched based on age with 16,112 patients without balanitis. By the end of the 12-year follow-up, the patients with balanitis had a significantly higher cumulative incidence of HZ than the non-balanitis patients. The risk of HZ for patients without comorbidities was 1.54-fold higher in the balanitis cohort than in the non-balanitis cohort. The higher risk of HZ occurred during the first 6 years of follow-up after a diagnosis of balanitis. Balanitis is a risk factor for HZ. Men with balanitis have a higher risk of developing HZ. HZ vaccination might be necessary for men with balanitis.