Analysis of optic neuritis risk in patients with allergic diseases.

The association between allergic diseases and optic neuritis (ON) remains insufficiently characterized. This nationwide cohort study investigated the relationship between major allergic diseases (atopic dermatitis, asthma, and allergic rhinitis) and the risk of ON development. We performed a population-based cohort study utilizing data from the Korean National Health Insurance Service database. The study included 4,052,827 individuals aged 20 years or older who participated in health screenings in 2009. All participants were monitored until December 2018 or until ON diagnosis. Cox proportional hazards models were applied to estimate hazard ratios (HRs) for ON, adjusting for relevant confounders. Over a median follow-up duration of 8.2 years, 3,640 individuals (0.09%) were diagnosed with ON. After adjusting for confounders, individuals with allergic diseases exhibited a statistically significant increased ON risk compared to those without allergic diseases (adjusted HR 1.317, 95% confidence interval [CI] 1.216-1.426, p < 0.0001). Among the specific allergic diseases, allergic rhinitis showed the highest association (adjusted HR 1.335, 95% CI 1.229-1.450, p < 0.0001), whereas asthma and atopic dermatitis did not demonstrate statistically significant associations after adjustment. These results highlight potential common pathogenic mechanisms and underscore the importance of future studies to clarify the biological pathways connecting allergic diseases and ON.