When JAK Selectivity Matters: Worsening Urticaria and Recurrent Allergic Rhinitis After Switching From Baricitinib to Ritlecitinib in Alopecia Areata

Dear Editor, Janus kinase (JAK) inhibitors are important treatments for alopecia areata (AA), but differ in kinase selectivity.Baricitinib predominantly inhibits JAK1/2, whereas ritlecitinib selectively inhibits JAK3 and TEC-family kinases [1].However, whether switching between these agents affects concomitant allergic diseases remains unclear.Here, we report recurrent urticaria and allergic rhinitis after switching from baricitinib to ritlecitinib.