Interventions for chronic palmoplantar pustulosis: abridged Cochrane systematic review and GRADE assessments.

Background Palmoplantar pustulosis (PPP) is a chronic inflammatory disease in which sterile and relapsing pustules appear on the palms and soles. Objectives To assess the effects of interventions for chronic PPP to induce and maintain complete remission. Methods We searched for randomised controlled trials (RCTs), including people with PPP or chronic palmoplantar pustular psoriasis, in Cochrane Skin Specialised Register, CENTRAL, MEDLINE, Embase, LILACS and eight trials registers up to July 2020. Study selection, data extraction and risk of bias assessment were carried out independently by two review authors. Certainity of evidence was assessed using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) method. Results We included 37 RCTs (1663 participants, 76% women, mean age 50 years).. Mean treatment duration was 11 weeks. Topical vitamin D derivative may be more effective than placebo in achieving clearance [risk ratio (RR) 7.83, 95% confidence interval (CI) 1.85 to 33.12; low-certainity evidence from 2 trials].. Concerning biologic therapies, there was little or no difference between etanercept and placebo in achieving clearance (low-certainity evidence from one trial), ustekinumab is less effective than placebo in reducing severity (low-certainty evidence from one trial), guselkumab and secukinumab probably better reduce disease severity (RR 2.88, 95% CI 1.24 to 6.69 and 1.55, 95% CI 1.02 to 2.35 respectively, moderate-certainty evidence from 2 and one trial respectively) but may cause more serious adverse events when compared to placebo. Conclusions Evidence is lacking for or against major chronic PPP treatments. Risk of bias and imprecision limit our confidence in the results.