The introduction of Janus Kinase inhibitors (JAKi) seems to revolutionize the field of alopecia areata (AA) therapeutics. However, the ideal JAKi is not yet settled and the real-world data are still missing. To provide evidence about effectiveness and safety of different JAKi including tofacitinib, baricitinib, ritlecitinib，abrocitinib, upadacitinib and ifidancitinib in real-world settings and describe baseline disease characteristics and patients profiles that are considered good candidates for JAKi in the daily practice. Furthermore, we intended to investigate the efficacy and safety of JAK Inhibitors in patients With AA, as well as to provide clinical evidence for the clinicians and patients when they formulate individualized treatment plans.

Inclusion Criteria:

• Patients with alopecia areata between 2 to 18 years old
• Patients diagnosed with alopecia areata according to AA guideline
• AA Patients treated with JAKi including tofacitinib, baricitinib, ritlecitinib，abrocitinib, upadacitinib and ifidancitinib for more than 3 months

Exclusion Criteria:

• Patients had previously received hair implants
• Other alopecia
• Other diseases may induce alopecia including psoriasis, lichen planus, et al.
• Unable to estimate SALT score at baseline or at follow-up
• Patients are participating in other clinical trials

Patients diagnosed with alopecia areata treated with JAKi including tofacitinib, baricitinib, ritlecitinib，abrocitinib, upadacitinib and ifidancitinib for more than 3 months in Department of Dermatology, Second Affiliated Hospital, Zhejiang University School of Medicine