A Seoul National University Bundang Hospital (SNUBH) research team has found that higher psoriasis severity was associated with a higher incidence of uveitis, which can cause blindness.

Psoriasis is a chronic, inflammatory, immune-mediated skin disease characterized by red rashes with thick scaling on the skin, which affected 160,000 patients in Korea in 2021.

Psoriasis is also often accompanied by uveitis, and unlike cataracts and glaucoma, which tend to occur in the elderly, uveitis can occur at any age or gender and can lead to blindness if untreated.

Recently, large-scale cohort studies have been conducted in Denmark and Taiwan to confirm the association between psoriasis and uveitis, but they were limited by the fact that they only confirmed the overall association and did not precisely identify the pattern and type of uveitis according to the severity of psoriasis.

In addition, there were no large-scale studies targeting Koreans, making it difficult to establish treatment guidelines optimized for Koreans.

Therefore, the team, led by Professors Woo Se-joon, Youn Sang-woong, Choi Chong-won, and Kim Bo-ri at the hospital, conducted a large-scale cohort study by comparing uveitis data from 320,000 psoriasis patients aged 20 years and older diagnosed and 640,000 patients suffering from uveitis without psoriasis from 2011 to 2021 based on data from the Health Insurance Review and Assessment Service.

As a result, the team found that the risk of uveitis was significantly increased in patients with psoriasis compared to those without, while uveitis symptoms and outcomes also worsened according to the severity of psoriasis.

For panuveitis, the type of uveitis with the highest risk of blindness, the difference in incidence between those with and without psoriasis was minimal.

However, in psoriasis accompanied by psoriatic arthritis, the risk of panuveitis increased dramatically, with an incidence rate of 0.44 per 1,000 person-years, more than double that of non-psoriatic patients.

The researchers also found that the probability of uveitis recurrence was highest within three years after the initial diagnosis of psoriasis.

"This is the first study to analyze in detail the risk of uveitis in Korean psoriasis patients through a large cohort study," Professor Woo said. "We recommend that patients with psoriasis undergo regular check-ups for visual problems, especially if their psoriasis is severe or accompanied by arthritis."

Professor Youn also said, "As a disease caused by immunologic abnormalities, psoriasis should not be taken lightly due to the high risk of complications, including uveitis."

The results of the study were pulibshed in the Journal of The European Academy of Dermatology & Venereology.