Abstract: Baricitinib is approved for the treatment of severe alopecia areata, but some patients do not respond well. It has been reported that upadacitinib is effective in the treatment of alopecia areat. We report two cases of severe alopecia areata (AA) patients who received baricitinib for 12 weeks without efficacy , and then switched to upadacitinib treatment, achieving significant therapeutic effects. After 40 weeks of treatment, patient 1’s hair volume returned to over 70% of normal level, and eyebrow regeneration was also improved significantly. Patient 2 returned to normal volume after 16 weeks of treatment. This study confirms the efficacy of upadacitinib in promoting hair regrowth, providing a new treatment option for patients with severe AA patients who have not responded to baricitinib.

Key words: JAK inhibitors, baricitinib, upadacitinib, alopecia areata