The risk of laryngitis with herpes zoster infection: A nested case-control study using data from the Korean National Sample Cohort

Background Whether herpes zoster infection (HZI) affects laryngitis incidence remains unknown. Objective The purpose of this population-based retrospective study was to analyze the relationship between laryngitis and HZI using data from the Korean Health Insurance Review and Assessment Service—National Sample Cohort. Methods This study analyzed 1,197,093 medical claim codes from 2018. Patients with HZI (ICD-10: B02) were retrospectively identified. Laryngeal diseases were defined by ICD-10 codes for five subgroups: 1) malignant disease, 2) benign disease, 3) vocal cord palsy, 4) inflammatory disease, and 5) reflux disease. Results Among the Korean population older than 20 years, 12,809 experienced HZI. Subjects with HZI were more likely to be older (mean age: 51.54 years vs. 48.06 years, p <0.0001). The proportion of subjects with laryngeal disease was higher in those with HZI than in those without HZI (55.55% vs. 41.37%, p <0.0001). Laryngeal disease was significantly associated with HZI in multiple regression analysis (odds ratio (OR) = 1.77, 95% confidence interval: 1.71–1.84) after adjusting for age, sex, hypertension, diabetes, dyslipidemia, ischemic heart disease, cerebral stroke, and depression. Among laryngeal disease subgroups, inflammatory disease (OR = 1.05; 95% CI: 1.01–1.09) and reflux (OR = 1.20; 95% CI: 1.15–1.25) were associated with HZI. Conclusions HZI is independently associated with laryngitis. Results of this study have implications for etiological investigations and prevention strategies for laryngitis.