TOPLINE: 

A nationwide cohort study of more than 4 million adults showed that people with allergic diseases were nearly one third more likely to develop optic neuritis than those without such conditions, with allergic rhinitis showing the strongest association with the increased risk.

METHODOLOGY:

• Researchers performed a population-based cohort study using data from a South Korean database to investigate the association between allergic diseases and the development of optic neuritis.
• A total of 4.05 million people aged 20 years or older who participated in health screenings in 2009 were monitored until December 2018, a diagnosis of optic neuritis, death, or emigration; those with a prior diagnosis of optic neuritis and those who developed the condition within 1 year of enrollment were excluded from the analysis.
• At least one allergic disease at baseline was seen in 636,779 participants.
• The analysis focused on three primary allergic diseases: atopic dermatitis, asthma, and allergic rhinitis.

TAKEAWAY:

• During the follow-up period, 3640 new cases of optic neuritis were identified.
• After adjustment for confounding factors, people with allergic diseases had a significantly higher risk for optic neuritis than those without (hazard ratio [HR], 1.317; P < .0001).
• Allergic rhinitis was most strongly associated with an increased risk for optic neuritis (adjusted HR, 1.335; P < .0001).
• No significant associations were found between asthma or atopic dermatitis and the risk for optic neuritis.

IN PRACTICE:

The findings suggest “allergic conditions and autoimmune-related optic nerve inflammation may involve overlapping pathogenic pathways,” according to the researchers. “These results are highly relevant for clinical management and public health…. Effective management of allergic symptoms and inflammatory processes may potentially lower the risk of optic neuritis,” they added.

SOURCE:

The study was led by Jaeryung Kim, of Sungkyunkwan University School of Medicine in Seoul, South Korea. It was published online on October 3, 2025, in Scientific Reports.

LIMITATIONS:

The identification of allergic diseases and optic neuritis relied on standard diagnostic codes, which may have introduced misclassification. The study lacked detailed information about severity of allergic conditions and specific therapeutic interventions. While the database provided information on corticosteroid prescriptions, crucial details about medication dosages, duration, and potency were unavailable. 

DISCLOSURES:

The study received financial support from the National Research Foundation, Ministry of Science and ICT, South Korea, and a grant from the Korea Health Industry Development Institute, Ministry of Health and Welfare, South Korea. The authors reported having no competing interests.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.