Prescription topical corticosteroids (steroids/cortisone creams utilizing an active ingredient such as desoximetasone) have been used for years as the first-step approach in the treatment of psoriasis. Cortisones reduce inflammation, itching, and potentially reduce cell buildup. Brands differ in potency, and the more powerful the drug, the higher the risk of more severe side effects, which include burning, irritation, dryness, acne, thinning of the skin, dilated blood vessels, and loss of skin color. Less potent drugs should be used for mild to moderate psoriasis, saving the high-potency drugs for more severe conditions. An effective regimen uses high-potency cortisones, such as halobetasol (Ultravate), daily until the psoriasis plaque flattens out, after which they are applied only on the weekends.
Another high-potency corticosteroid, mometasone (Elocon), needs to be administered only once a day and is as effective—or more effective—than other corticosteroids while having a lower risk of severe side effects. These very potent drugs carry a small risk of causing hormonal problems for a period of time after the drug has been withdrawn. The larger the area treated with corticosteriods, the higher the risk, especially if the area is covered by heavy material or is bandaged. Also, in most cases, resistance to these drugs eventually develops; and the disease can recur after treatment is stopped (Source: http://my. webmd. com/content/article/1680.51881).
Low – to mid-potency topical steroids are good for short-term treatment, limited to a 2-4 week duration. It is recommended that their use be of limited duration to minimize the risks associated with topical steroids, such as collagen depletion and skin thinning. Topical steroids are more effective than calcipotriene (calcipotriol, or vitamin D3), pimecrolimus, and tacrolimus, but those treatments are associated with fewer long-term risks and are therefore recommended for long-term therapy when possible, perhaps when alternated with cortisones. Another negative of using cortisone is that with continued use it becomes less and less effective. (Sources: Journal of the American Academy of Dermatology, January 2009, pages 120-124; and Journal ofthe European Academy of Dermatology and Venerology, July 2008, pages 859-870.)