Topical treatments for chronic plaque psoriasis: an abridged Cochrane systematic review.

BACKGROUND: Chronic plaque psoriasis is the most common type of psoriasis and is characterized by redness, thickness, and scaling. First-line management is with topical treatments. OBJECTIVE: We sought to undertake a Cochrane review of topical treatments for chronic plaque psoriasis. METHODS: We systematically searched major databases for randomized controlled trials. Trials reported improvement using a range of related measures; standardized, pooled findings were translated onto a 6-point improvement scale. RESULTS: The review included 177 randomized controlled trials with 34,808 participants, including 26 trials of scalp psoriasis and 6 trials of inverse and/or facial psoriasis. Typical trial duration was 3 to 8 weeks. When compared with placebo (emollient base), the average improvement for vitamin-D analogues and potent corticosteroids was approximately 1 point, dithranol 1.2 points, very potent corticosteroids 1.8 points, and combined vitamin-D analogue plus steroid 1.4 points once daily and 2.2 points twice daily. However, these are indicative benefits drawn from heterogeneous trial findings. Corticosteroids were more effective than vitamin D for treating psoriasis of the scalp. For both body and scalp psoriasis, potent corticosteroids were less likely than vitamin D to cause skin irritation. LIMITATIONS: Reporting of benefits, adverse effects, and safety assessment methods was often inadequate. In many comparisons, heterogeneity made the size of treatment benefit uncertain. CONCLUSIONS: Corticosteroids are as effective as vitamin-D analogues and cause less skin irritation. However, further research is needed to inform long-term maintenance treatment and provide appropriate safety data.