A large-scale South Korean study found that COVID-19 infections may have been associated with an increased long-term risk of 11 autoimmune and autoinflammatory disorders, with higher risks observed in patients who experienced severe infections, were infected during the Delta variant period, or were unvaccinated.
In the nationwide population-based study, published in JAMA Dermatology, investigators analyzed the data from 6.9 million participants (53.6% male, mean age = 53.39 years), including 3.1 million patients with COVID-19 infections and 3.8 million controls, with a mean follow-up period of 287 days.
The investigators found significantly increased risks for multiple conditions in the patients with COVID-19 infections compared with controls, including alopecia areata (adjusted hazard ratio [HR] = 1.11), alopecia totalis (adjusted HR = 1.24), vitiligo (adjusted HR = 1.11), Behçet disease (adjusted HR = 1.45), Crohn's disease (adjusted HR = 1.35), ulcerative colitis (adjusted HR = 1.15), rheumatoid arthritis (adjusted HR = 1.09), systemic lupus erythematosus (adjusted HR = 1.14), Sjögren's syndrome (adjusted HR = 1.13), ankylosing spondylitis (adjusted HR = 1.11), and bullous pemphigoid (adjusted HR = 1.62).
The risk increase was particularly pronounced among ICU patients, with notably elevated risks for sarcoidosis (AHR, 4.12), Sjögren syndrome (AHR, 2.85), systemic lupus erythematosus (AHR, 2.22), and bullous pemphigoid (AHR, 6.82).
The Delta variant period showed substantially higher risks compared with the Omicron period, including alopecia totalis (adjusted HR = 2.51), systemic lupus erythematosus (adjusted HR = 2.50), and ulcerative colitis (adjusted HR = 2.47).
Gender-specific analysis revealed men had higher risks for vitiligo (adjusted HR = 1.24), Crohn's disease (adjusted HR = 1.55), and ulcerative colitis (adjusted HR = 1.31), whereas women showed increased risks for alopecia totalis (adjusted HR = 1.32) and bullous pemphigoid (adjusted HR = 2.11).
Age stratification demonstrated that patients under 40 years had higher risks for primary cicatricial alopecia (adjusted HR = 1.54) and Behçet disease (adjusted HR = 1.66).
The research team, led by Solam Lee, MD, PhD, from Yonsei University Wonju College of Medicine, utilized comprehensive national health data. The study included COVID-19 cases confirmed through polymerase chain reaction testing prior to March 2022 and physician-confirmed rapid antigen tests thereafter. Study validity was strengthened through the use of both positive control outcomes (heart failure) and negative control outcomes (epidermal cysts).
The authors declared having no competing interests.
