*Review* **Application of Janus Kinase Inhibitors in Atopic Dermatitis: An Updated Systematic Review and Meta-Analysis of Clinical Trials**

**Hou-Ren Tsai 1 , Jing-Wun Lu 2 , Li-Yu Chen <sup>3</sup> and Tai-Li Chen 1,4, \***


**Abstract:** Janus kinase (JAK) inhibitors are promising treatments for atopic dermatitis (AD). The aim of this study was to assess the efficacy and safety of JAK inhibitors for AD treatment via the "Grading of Recommendations Assessment, Development, and Evaluation" approach. We identified 15 randomized controlled trials comparing oral or topical JAK inhibitors against placebo to treat AD. A random-effects meta-analysis was performed, and the numbers-needed-to-treat (NNTs)/numbersneeded-to-harm (NNHs) were calculated. Patients treated with JAK inhibitors were associated with higher rates of achieving eczema area and severity index-75 (rate ratio (RR): 2.84; 95% confidence interval (CI): 2.20–3.67; I 2 : 38.9%; NNT = 3.97), Investigator's Global Assessment response (RR: 2.99; 95% CI: 2.26–3.95; I 2 : 0%; NNT = 5.72), and pruritus numerical rating scale response (RR: 2.52; 95% CI: 1.90–3.35; I 2 : 39.4%; NNT = 4.91) than those treated with placebo. Moreover, patients treated with JAK inhibitors had a higher risk of treatment-emergent adverse events (RR: 1.14; 95% CI: 1.02–1.28; I 2 : 52%; NNH = 14.80) but not adverse events leading to drug discontinuation. According to the evidence-based results, JAK inhibitors are potentially effective strategies (certainty of evidence: "moderate") for treating AD with tolerable side effects (certainty of evidence: "low"). Nevertheless, long-term follow-up is required.

**Keywords:** atopic dermatitis; eczema; JAK inhibitors; systematic review; meta-analysis; evidence-based medicine; immune-mediated skin diseases; target therapy; skin conditions and systemic inflammatory diseases
