Janus kinase inhibitors, also known as JAK inhibitors, are a novel drug class that targets and blocks cytokine signaling mediated by the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway, thus regulating immune response and cell growth. 

Despite the primary use of JAK inhibitors for rheumatological conditions such as rheumatoid arthritis, their application is now investigated in dermatology. Tofacitinib is US Food and Drug Administration (FDA)-approved drug for psoriatic arthritis and has shown promising results in treating psoriasis. Ruxolitinib recently gained regulatory approvals for the US as a first-in-class, selective topical therapy for atopic dermatitis. Also, oral upadacitinib achieved the same for treating active psoriatic psoriasis. Furthermore, abrocitinib and upadacitinib have displayed efficacy in treating atopic dermatitis; however, their FDA approval for this indication is pending. 

In clinical trials, the JAK inhibitors have shown promising therapeutic potential for treating dermatological conditions such as alopecia areata, psoriasis, atopic dermatitis, vitiligo and dermatomyositis. Their adverse events seem to be indifferent to that of biologic drugs, with common effects being increased risk of infections and thromboembolic events.

With more robust studies assessing their long-term safety and establishing treatment guidelines, JAK inhibitors will become important additions to the therapeutic arsenal for many inflammatory skin conditions.

Further investigation is warranted to understand the safety profile of JAK inhibitors better and utilize them fully within the field of dermatology.

Source: Shalabi MMK, Garcia B, Coleman K, et al. Janus kinase and tyrosine kinase inhibitors in dermatology: a review of their utilization, safety profile and future applications. Skin Therapy Lett. 2022;27(1):4-9.