Topical Janus kinase inhibitors: A review of applications in dermatology.

Background: Janus kinase (JAK) inhibitors have attracted attention for their role in treating inflammatory disorders. This new class of biologics has the potential to significantly affect the field of dermatology, especially with the development of topical formulations.

Objective: To summarize published evidence on the efficacy, safety, and tolerability of topical JAK inhibitors in the treatment of inflammatory skin conditions.

Methods: This is a review of articles available in PubMed and the Cochrane Library up until November 2017.

Results: Fifty-five potential articles were identified; 11 articles were included for review, comprising an aggregate of 924 patients. In randomized clinical trials, topical JAK inhibitors demonstrate modest improvements in psoriasis and atopic dermatitis disease scores, patient-reported outcomes, and quality of life. Results for vitiligo are conflicting, with improvements seen only in facial vitiligo. Conclusive efficacy data for alopecia areata is lacking.

Limitations: It was not possible to perform a meta-analysis due to the lack of standardization and low number of randomized clinical trials.

Conclusion: Topical JAK inhibitors provide an attractive treatment option for patients with psoriasis, atopic dermatitis, alopecia areata, and vitiligo. Although early phase clinical studies of this novel drug class are promising, large phase 3 and 4 studies are needed to further define the role of topical JAK inhibitors in dermatology.