How effective are topical treatments for chronic plaque psoriasis?
Vitamin D products are more effective than emollients. Potent corticosteroids (eg, betamethasone diproprionate) and very potent corticosteroids (eg, clobetasol propionate) are also effective, and very potent corticosteroids are more effective than either potent corticosteroids or vitamin D products alone. Combined vitamin D and potent corticosteroids are more effective than either treatment alone. Corticosteroids appear to be more effective than vitamin D for treating psoriasis of the scalp. The effectiveness of dithranol and tazarotene appears to be similar to that of vitamin D products. Potent corticosteroids are less likely than vitamin D to cause local adverse effects, such as skin irritation. Tazarotene is more likely to cause local adverse events than placebo.
It was not possible to assess the performance of treatments at different levels of severity of psoriasis. There seemed to be no difference between placebo and any other treatment in terms of systemic adverse events, but many trials did not properly assess systemic adverse events.
Chronic plaque psoriasis is the commonest type of psoriasis. First-line management involves topical treatments, including vitamin D analogues, topical corticosteroids, tar-based preparations, dithranol, salicylic acid and topical retinoids, such as tazarotene.