Emerging role of topical Janus kinase inhibitors in dermatological disorders: a review

Janus kinase (JAK) refers to a family of tyrosine kinases that are involved in the production of proinflammatory mediators in response to various extracellular signals. The JAK-signal transducer and activator of transcription (STAT) pathway is an appealing target in many inflammatory illnesses as this pathway modulates immune cell activation and T-cell-mediated inflammation in response to several cytokines. The practical considerations of prescription for topical and oral JAK inhibitors (JAKis) in atopic dermatitis, vitiligo and psoriasis have been covered in prior publications. Currently, the US Food and Drug Administration has approved the topical JAKi ruxolitinib for atopic dermatitis and nonsegmental vitiligo. None of the remaining first- or second-generation topical JAKis have been approved for topical application in any dermatological indications so far. For this review, the PubMed database was searched using 'topical' and 'JAK inhibitor' or 'Janus kinase inhibitor' or the names of individual drug molecules as the keyword in the title with no date limits. The description of topical JAKi usage in dermatology from the literature was evaluated in each abstract. The current review concentrates on emphasizing the rising use of topical JAKis in both approved and off-label dermatological applications for both old and novel conditions. Currently, the Food and Drug Administration has approved the topical Janus kinase inhibitor (JAKi) ruxolitinib for atopic dermatitis and nonsegmental vitiligo. None of the remaining first- or second-generation topical JAKis have been approved for topical application in any dermatological indications so far. The current review concentrates on emphasizing the rising use of topical JAKis in both approved and off-label dermatological applications for both old and novel conditions.