Janus Kinase Inhibitors for Treatment of Palmoplantar Pustulosis, Generalized Pustular Psoriasis, and Palmoplantar Pustular Psoriasis: A Systematic Review of the Literature

Introduction: Palmoplantar pustulosis (PPP) is a chronic, recurrent, inflammatory disease and assumed to be a subtype of psoriasis. Pustular psoriasis (PP) is a chronic inflammatory disease that is further subclassified into various entities with different presentations including generalized pustular psoriasis (GPP) and palmoplantar pustular psoriasis (PPPP). Given the central role of the JAK-STAT pathway in cytokine signaling, this systematic review evaluated the effectiveness and safety of Janus kinase inhibitors (JAK-I) in these PP subtypes. Methods: Following PRISMA 2020 guidelines, a systematic search was conducted across PubMed/Medline, Scopus, Web of Science, and Embase up to November 13, 2025. Eligible studies included assessing JAK-I in PPP, GPP, or PPPP. Exclusion criteria were reviews, articles without full-text, SAPHO syndrome, and animal/in vitro studies. Risk of bias was assessed using the NHLBI quality assessment tool for clinical studies and Murad et al.'s checklist for case reports/series. Results: = 5) achieved rapid clearance or marked improvement within 2-12 weeks. Adverse events (18.7%) were generally mild, most commonly acneiform eruptions, headache, and transient liver enzyme elevations, with no severe events reported. Conclusion: JAK-I demonstrate high response rates and rapid improvement with manageable safety profiles. However, the current evidence is limited by small sample sizes, short follow-up durations, and reliance on case-based data. They represent a promising therapeutic option and warrant further evaluation in larger controlled studies to establish long-term efficacy and safety.