Treatment of palmoplantar psoriasis with infliximab: a randomized, double‐blind placebo‐controlled study

Abstract

Background Palmoplantar psoriasis is a difficult to treat variant of plaque psoriasis. Objective To study the safety and efficacy of infliximab in non‐pustular palmoplantar psoriasis. Methods Patients with non‐pustular palmoplantar psoriasis affecting at least 10% of their palms and soles and with a modified palmoplantar psoriasis area and severity index (m‐PPPASI) of at least eight were recruited. Patients were randomized (1:1) to receive infliximab 5 mg/kg or placebo at weeks 0, 2 and 6. Patients initially randomized to placebo received infliximab at weeks 14, 16 and 20 whereas patients randomized to infliximab received additional infliximab infusions every 8 weeks until week 22. Results Twenty four (24) patients were randomized in this study. At week 14, 33.3% and 66.7% of patients treated with infliximab achieved m‐PPPASI 75 and m‐PPPASI 50 respectively compared to 8.3% for both m‐PPPASI 75 (P = 0.317) and m‐PPPASI 50 (P = 0.009) for patients randomized to placebo. A reduction of 50.3% in the mean surface area of palms and soles affected with psoriasis was seen at week 14 in patients randomized to infliximab as compared to an increase of 14.9% in patients randomized to placebo (P = 0.009). Conclusions This pilot study did not reach its primary endpoint of m‐PPPASI 75 at week 14. However, infliximab was observed to be more efficacious than placebo in improving PPSA and with respect to the percentage of patients reaching m‐PPPASI 50 at week 14. Larger and longer term studies are needed for severe patients to better assess the efficacy of infliximab in palmoplantar psoriasis.