Effectiveness of Apremilast in Patients With Palmoplantar Pustulosis: A 28-Week Real-World Study

Apremilast, an oral phosphodiesterase 4 (PDE4) inhibitor, has been reported to be effective and tolerable for moderate-to-severe palmoplantar pustulosis (PPP) in clinical trials, but real-world data are limited. To evaluate the 28-week real-world effectiveness of apremilast in patients with PPP. We conducted a single-center, retrospective study of 15 adult patients (≥ 18 years) with moderate-to-severe PPP (baseline physician's global assessment score ≥ 3) who required systemic treatment because topical therapy alone was insufficient or unsuitable. Patients received apremilast 30 mg twice daily. Palmoplantar Pustulosis Area and Severity Index (PPPASI) and Dermatology Life Quality Index (DLQI) were assessed at weeks 0, 4, 16, and 28 of treatment. Mean PPPASI and DLQI scores decreased continuously through Week 28. At Week 28, mean percent reductions of PPPASI and DLQI from baseline were 76.9% and 63.4%, respectively. Week 28 rates achieving PPPASI 50, PPPASI 75, PPPASI 90, and DLQI 0/1 were 90.0%, 60.0%, 30.0%, and 42.9%, respectively. Treatment-emergent adverse events were diarrhea in six patients, leading to discontinuation of apremilast in one patient. No serious adverse events occurred. These findings suggest that apremilast treatment is effective and tolerable for PPP patients requiring systemic treatment in routine practice. Further studies with larger cohorts and longer observation are required to confirm the sustainability of its clinical benefits.