Baricitinib in the Management of Severe Alopecia Areata: A Report of Two Cases with Sustained Clinical Response

Alopecia areata (AA) is an autoimmune condition marked by hair loss due to the collapse of hair follicle immune privilege, primarily driven by CD8⁺NKG2D⁺ T cells and inflammatory cytokines like IFN-γ. Various immune cells, including Th1, Th2, Th17, γδT, NK, and mast cells, contribute to this process, with Tregs, Bregs, and iNKT cell dysfunction exacerbating the imbalance. The JAK-STAT pathway is a key regulatory node, and JAK inhibitors have shown clinical effectiveness, with some receiving FDA approval for moderate-to-severe AA. However, the efficacy of targeting IL-17, TNF-α, Th2 cytokines, and PDE4 is still debated. The review highlights the need for further research into AA's immune regulation and tailored treatments to improve patient outcomes.