Status praesens van de Janus Kinase-inhibitoren: een veelbelovend behandelingsperspectief in de dermatologie

Status praesens of Janus Kinase Inhibitors: a promising therapeutic option in dermatology Janus kinase inhibitors (JAKi) represent a relatively recent addition to the drug class of immunomodulators. As the Janus kinase–signal transducer and activator of transcription (JAK-STAT) pathway is involved in a broad range of inflammatory responses, they are potentially applicable in a wide array of immunological processes. Initially, JAKi were primarily used in oncological or immune-mediated systemic disorders. The aim of this article is to provide a systematic literature review of the dermatological applications as well as the clinical implications of this new drug class (e.g. indications, common side effects, necessary precautions before initiation, and the parameters for monitoring in chronic usage). The immune-mediated dermatoses for which the effectiveness of JAKi has been proven are in general complex and multifactorial conditions. In Belgium, only 4 JAKi are currently registered, exclusively for the treatment of atopic dermatitis, alopecia areata, and psoriasis. The FDA has also approved the use of JAKi in vitiligo, as well as topical JAKi, which lead to less systemic absorption. In case studies, JAKi have also already proven effective in the treatment of many other immune-mediated dermatoses. JAKi are generally only indicated after the failure of previous immunosuppressive therapies. In addition to financial concerns, this cautious approach in prescribing JAKi can be explained by concerns about side effects. The safety profile of JAKi, especially when limited to dermatological applications, is generally mild. The most frequently reported side effects are gastrointestinal complaints (nausea, diarrhea), headaches, upper respiratory tract infections, and urinary tract infections. In light of these side effects, the initiation of JAKi requires individualized assessment and ongoing monitoring, including screening for comorbidities and risk factors, excluding contra-indications, determining baseline values and informing the patient.