Topical treatments for chronic plaque psoriasis.
BACKGROUND
Chronic plaque psoriasis is the most common type of psoriasis and is characterised by redness, thickness and scaling. First line management of chronic plaque psoriasis is with topical treatments, including vitamin D analogues, topical corticosteroids, tar-based preparations, dithranol, salicylic acid and topical retinoids.


OBJECTIVE
To compare the effectiveness, tolerability and safety of topical treatments for chronic plaque psoriasis with placebo; to compare vitamin D analogues with other topical treatments.


METHODS
The Cochrane Skin Group's Trials Register was searched (2004/12). To update an unpublished 2002 review we also searched CENTRAL in The Cochrane Library (Issue 1,2005); MEDLINE (to 2005/02); EMBASE (to 2005/08); Science Citation Index (to 2005); Biosis (to 2005); Dissertation Abstracts (all publication years); Inside Conferences (all publication years); SIGLE (to 2005); National Research Register (all projects with a start date of 2001 to 2005); metaRegister of Current Controlled Trials.


METHODS
Randomised trials comparing treatments against placebo or against vitamin D analogues in people with chronic plaque psoriasis.


METHODS
One author extracted study data and assessed study quality. A second author checked these data. We routinely contacted triallists and companies for missing data. We extracted data on withdrawals and adverse events.


RESULTS
The review included 131 RCTs with 21,448 participants. Vitamin D was significantly more effective than placebo, although there was a wide variation in effect size with the standardised mean difference (SMD) ranging from -0.82 (95% CI -1.34 to -0.29) to -1.90 (95% CI -2.09 to -1.71). With one exception, all corticosteroids performed better than placebo, with potent corticosteroids (SMD: -0.95 (95% CI: -1.11 to -0.80; I(2): 61.1%; 17 studies; 2386 participants)) having smaller benefits than very potent corticosteroids (SMD: -1.29 (95% CI: -1.45 to -1.13; I(2): 53.2%; 11 studies; 1571 participants)). Dithranol and tazarotene performed better than placebo. Head-to-head comparisons of vitamin D against potent or very potent corticosteroids found no significant differences. However, combined treatment with vitamin D /corticosteroid performed significantly better than either vitamin D alone or corticosteroid alone. Vitamin D performed better than coal tar, but findings relative to dithranol were mixed. Potent corticosteroids were less likely than vitamin D to cause local adverse events. No comparison of topical agents found a significant difference in systemic adverse effects.


CONCLUSIONS
Corticosteroids perform as well as vitamin D analogues and are associated with a lower incidence of local adverse events. Further research is required to inform long-term maintenance treatment.
Centre for Health Economics, University of York, Alcuin A Block, Heslington, York, UK, YO10 5DD. arm10@york.ac.uk
Anne R
AR
Mason
James
J
Mason
Michael
M
Cork
Gordon
G
Dooley
Gladys
G
Edwards
D000287:Administration, Topical; D000305:Adrenal Cortex Hormones / Q000009:adverse effects / Q000627:therapeutic use*; D050071:Bone Density Conservation Agents / Q000009:adverse effects / Q000627:therapeutic use*; D002908:Chronic Disease; D006801:Humans; D011565:Psoriasis / Q000188:drug therapy*; D016032:Randomized Controlled Trials as Topic; D014807:Vitamin D / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use
D000305:Adrenal Cortex Hormones; D050071:Bone Density Conservation Agents; D014807:Vitamin D