Background  Despite the chronicity of psoriasis, most systematic reviews focus on short-term treatment.

Methods  The systematic search strategy and results from the German Psoriasis Guidelines were adapted. To update the data a literature search in Medline, Embase and the Cochrane Library was conducted. The proportion of participants achieving ≥75% decrease in Psoriasis Area and Severity Index (PASI) as well as Dermatology Life Quality Index (DLQI) reduction at different time points were assessed. Trials were summarized with respect to time periods and study designs. Suitable trials were included in a meta-analysis. Particular attention was paid to statistical approaches of handling dropouts.

Results  A total of 33 articles including 27 trials totaling 6575 patients with active treatment were included in the systematic review. Seven randomized controlled trials were eligible for the meta-analysis. Over a 24 week treatment period infliximab [risk difference (RD) 78%, 95% confidence interval (CI) 72–83%] and ustekinumab 90 mg every 12 weeks (RD 77%, 95% CI 71–83%) were the most efficacious treatments. Adalimumab (RD: 60%, 95% CI 45–74%) showed results within the range of different etanercept dosages (etanercept 50 mg once weekly: RD 62%, 95% CI, 52–72%), (etanercept 25 mg twice weekly: RD 45%, 95% CI 34–56%), (etanercept 50 mg twice weekly: RD 56%, 95% CI 49–62%) and (etanercept 50 mg twice weekly until week 12, then 25 mg twice weekly: RD 50%, 95% CI 42–57%). After 24 weeks a decrease in efficacy for inflximab, adalimumab and etanercept was observed.

Conclusions  More sufficient data is required to draw reliable conclusions in extended long-term treatment and head-to-head comparisons are necessary.