Introduction

Alopecia areata is a heterogenous, immune-mediated hair loss disorder that can affect any hair-bearing site on the body. Despite being one of the most prevalent autoimmune skin diseases, treatments have historically been limited to off-label medications that have demonstrated limited efficacy, especially in more severe forms of disease. Thus, there has long been an unmet need for rigorously studied therapeutics in alopecia areata.

Areas covered

Janus kinase inhibitors have proven to be an effective class of drugs for treating several inflammatory disorders. One such drug, baricitinib, has recently demonstrated significant hair regrowth in phase 2 and 3 alopecia areata trials. It has since become the first systemic therapy approved for treating severe alopecia areata. This review examines the role of Janus kinase pathways in alopecia areata's pathogenesis and the safety and efficacy of baricitinib for treating severe alopecia areata.

Expert opinion

The approval of baricitinib for treating severe alopecia areata marks a major milestone in the disease's history. While baricitinib has proven to be efficacious for this indication and has demonstrated an overall good safety profile, patients' individual risk factors for serious adverse events should be assessed during shared decision-making with patients before initiating treatment.