JAK inhibitors for alopecia areata: a systematic review and meta-analysis.

There have been a number of case reports and small clinical trials reporting promising outcomes of Janus Kinase (JAK) inhibitors tofacitinib, ruxolitinib and baricitinib for alopecia areata (AA). The majority of the literature to date is based on small volume data, with a lack of definitive evidence or guidelines. To determine the expected response of AA to JAK inhibitor therapy and factors which influence response and recurrence rates. A systematic review and meta-analysis was performed according to PRISMA guidelines. From 30 studies and 289 cases, there were 72.4% responders, good responders 45.7% and partial responders 21.4%. Mean time to initial hair growth was 2.2 ± 6.7 months, and time to complete hair regrowth was 6.7 ± 2.2 months. All 37 recurrences occurred when treatment was ceased after 2.7 months. Oral route was significantly associated with response to treatment compared to topical therapy. No difference was found between paediatric and adult cases in proportion of responses. There is promising low-quality evidence regarding the effectiveness of JAK inhibitors in AA. Future large-sized randomized studies are required to confirm findings.