Janus Kinase Inhibitors for Treatment of Palmoplantar Pustulosis, Generalized Pustular Psoriasis, and Palmoplantar Pustular Psoriasis: A Systematic Review of the Literature.
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
Thirty-seven studies were included (29 case reports, 4 case series, and 4 clinical studies), encompassing 157 patients (60.5% female; mean age 46.8 years). Treatments involved tofacitinib, upadacitinib, baricitinib, abrocitinib, and topical ruxolitinib. In PPP, pooled meta-analysis demonstrated a PPPASI-50 response rate of 85.5% (95% CI, 71.3-93.3), with upadacitinib achieving 90.9% (95% CI, 81.7-95.7). Case reports and series showed 88.1% clearance or near-clearance within a mean of 2.5 months. GPP patients (n = 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.
