Alopecia Universalis in an Adolescent Successfully Treated with Upadacitinib-A Case Report and Review of the Literature on the Use of JAK Inhibitors in Pediatric Alopecia Areata.

Alopecia areata (AA) is a cell-mediated autoimmune disease in which a cytotoxic T-cell response against hair follicles occurs. AA has been demonstrated to frequently co-exist with atopic dermatitis (AD), and the coincidence of atopy predisposes to a more severe course of the disease. To date, therapeutic options in AA, especially in the pediatric population, are mainly limited to corticosteroids, irritants, sensitizers, and immunosuppressive agents. Recently, innovative therapies have emerged, among which Janus kinase (JAK) inhibitors, effective in both AD and AA, appear to be the most promising. Here, a 14-year-old girl with alopecia universalis (AU) and mild AD is demonstrated, who was successfully treated with a selective JAK1 inhibitor, upadacitinib, which has been approved for the treatment of AD in adults and children aged 12 years and older. Resolution of eczema and complete hair regrowth was achieved after 3 months of therapy. Apart from transient mild leukopenia at weeks 4 and 8, no adverse events were noted. Data in the literature on the efficacy and safety of JAK inhibitors in the treatment of AA in the pediatric population is based on single case reports and case series. So far, topical tofacitinib and ruxolitinib, as well as systemic tofacitinib, ruxolitinib, and baricitinib have been used off-label in this indication in children. Upadacitinib is another effective treatment option with a good benefit-risk ratio for patients with AA, including cases coexisting with AD.