JAK Inhibitor Safety in Atopic Dermatitis and Alopecia Areata: A 4.5-Year Real-World Retrospective Cohort Study

This 4.5-year real-world retrospective cohort study evaluated the safety of JAK inhibitors (abrocitinib, baricitinib, upadacitinib, and ritlecitinib) in 376 adult patients with alopecia areata or atopic dermatitis. The study found that JAK inhibitors were generally well tolerated, with most adverse events being mild to moderate, such as mild cholesterol increases, weight gain, and upper respiratory infections. Serious adverse events like major cardiovascular events and aggressive cancers were rare. Notably, weight gain was more common in female patients, and menstrual alterations, though rare, were a significant cause of treatment discontinuation. The study underscores the importance of continuous real-world safety monitoring, particularly for metabolic and sex-specific side effects, as routine clinical practice is less controlled than clinical trials.