Disease features, treatments, and burden of palmoplantar pustulosis in Korea: The <scp>EPPPIK</scp> study

Palmoplantar pustulosis (PPP) is a chronic skin disease characterized by erythema, pustules, and desquamation of the palms and soles. PPP epidemiological data are scarce. Understanding disease characteristic is essential for effective management and to reduce burden. The objective of the study was to describe disease characteristics of PPP in Korea, including demographics, disease burden, and current clinical practice. This was a cross-sectional, multicenter, noninterventional study conducted among 20 sites in Korea. Patients (aged ≥19 years) with a confirmed PPP diagnosis were examined and interviewed, collecting clinical and patient-reported outcomes in 1 day. A total of 379 patients with PPP (mean age, 51.4 years; 39.3% male) were enrolled. The mean age at diagnosis was 47.9 years, and the mean duration of PPP was 3.2 years. Mean±standard deviation of Palmoplantar Pustulosis Area and Severity Index (PPPASI) score was 10.3±9.0; 33.8% of patients scored ≥12. PPPASI score was significantly higher with younger age (p = 0.0001) and nail involvement (p = 0.0002). Mean Dermatology Life Quality Index (DLQI) score was 12.0, and mean EuroQoL 5-Dimension Health Questionnaire (EQ-5D) score was 62.4 ± 19. Patients with PPPASI ≥12 had significantly higher DLQI (14.1 ± 7.3 vs 10.9 ± 7.6; p < 0.0001) and lower EQ-5D (57.9 ± 18.1 vs 64.7 ± 19.2; p = 0.002) scores. The most common treatments in patients with PPPASI <12 were topicals (50.6%), conventional therapies (34.7%), and retinoids (32.7%); the most common treatments with PPPASI ≥12 were conventional therapies (37.5%), topicals (34.4%), and retinoids (29.7%). Conventional therapy users were "more satisfied" than nonusers (49.6% vs 39.0%; p = 0.05), with a numerical difference observed for biologics (41.8% vs 63.1%; p = 0.07). PPP is a debilitating disease that significantly diminishes overall quality of life. Despite most patients receiving treatment, PPP burden persists. Developing treatment guidelines and identifying more targeted and effective treatments would help alleviate symptoms, reduce severity, and improve overall quality of life.