RESUMEN
Palmoplantar (PP) psoriasis is considered one of the most hard-to-treat areas with important impact on patients' quality of life, and few data are available about the efficacy of dimethylfumarate (DMF) on these areas. In our noninterventional multicentre retrospective cohort study of patients with PP psoriasis treated with DMF, effectiveness was evaluated as mean pp Psoriasis Area and Severity Index (ppPASI) reduction and as proportion of patients that reach ppPASI 75 at 4, 12, 24 and 48 weeks. The reduction in ppPASI was 23.5% at w4, 49.7% at w12, 69.1% at w24 and 81.1% at w48. pp Investigator's Global Assessment (ppIGA) 0/1 was reached by 5 patients (10.64%) at w4, 10 patients (23.8%) at w12, 11 patients (40.7%) at w24 and 12 patients (60%) at w48 confirming that DMF could represent an effective therapy in patients affected by PP psoriasis. Overall, the treatment was well tolerated although only 24 patients made it to 24 weeks of therapy and 28 patients completed the observation period at 48 weeks. None of the patients reported adverse events requiring discontinuation of the drug. However, this discontinuation rate is in line with clinical trials and real-world evidence.