Effect of Systemic Immunomodulators on Incidence of Alopecia Areata: A Retrospective Cohort Study

This retrospective cohort study analyzed data from over 275 million patients to assess the impact of systemic immunomodulators on the incidence of alopecia areata (AA) in individuals with primary autoimmune conditions. The study found that patients using leflunomide had a decreased risk of developing AA, with a relative risk of 0.478 compared to healthy controls. In contrast, methotrexate, cyclosporine, and rituximab were associated with an increased risk of AA, with relative risks of 2.192, 3.598, and 1.828, respectively. Additionally, disease-modifying antirheumatic drugs (DMARDs) and TNF‐α inhibitors were linked to a higher incidence of AA. The findings suggest that while leflunomide may reduce AA risk, other immunomodulators could potentially increase it.