Psoriatic plaques are dry, scaly and frequently itchy. Emollients may help to soften psoriatic scale by increasing its water content, either by forming an occlusive layer on the skin surface (for example white soft paraffin) or by an osmotic effect (for example urea containing creams). Most topically applied therapies for psoriasis are formulated in emollient bases but emollients on their own are frequently advocated for psoriasis. They are claimed to reduce dryness, scaling and itch. There is little published evidence documenting the efficacy of emollient therapy alone in the management of psoriasis, although many studies have compared the effects of emollient bases with the same bases containing "active" ingredients. Some evidence suggests that emollients may have a steroid-sparing effect in psoriasis managed with topical corticosteroids.
Occlusive dressings have also been used for treating psoriatic plaques, often to enhance penetration of active drugs such as topical corticosteroids, but they have also been examined on their own. Hydrocolloid gel dressings may be useful on their own for selected recalcitrant psoriatic plaques and may enhance the response to topical corticosteroids and calcipotriol.
Many studies have shown an improvement over baseline after regular application of emollient creams or ointments. In one open-label study in which within patient comparisons were made in two separate cohorts of 48 patients with chronic plaque psoriasis, the combination of a once-daily application of a water-in-oil cream or lotion with once-daily betamethasone dipropionate cream was found to be more effective than once-daily and of equal efficacy to twice-daily betamethasone dipropionate cream.12 In another within patient study (n = 43) the application of an oil-in-water emollient cream before UVB exposure significantly enhanced the rate of psoriasis improvement with UVB phototherapy. The authors suggest that the emollient may have altered the optical properties of the epidermis. Another small within patient study compared a 10% urea ointment with its base or with no therapy (n = 10). Two weeks' therapy with the urea ointment produced a >50% reduction in clinical score compared with the untreated side; however, the ointment base alone also produced a significant improvement in clinical score.13 In another RCT (n = 40), a 12% urea and 12% sodium chloride cream was shown to be superior to the cream base and to have comparable efficacy to salicylic acid ointment at removing scale from psoriatic plaque.14
In a small open prospective bilateral comparison study involving 26 patients with stable symmetrical plaque psoriasis, 47% of treated plaques resolved after weekly applications of an adhesive hydrocolloid occlusive dressing for 10 weeks. Furthermore, the dressing was found to be more effective than twice-daily applications of a potent corticosteroid cream (fluocinolone acetonide) for 10 weeks (12% resolution rate) although less effective than erythemogenic UVB phototherapy
How effective are treatments for limited stable chronic plaque psoriasis?
given five times weekly for the same duration (67% resolution rate).15 The results from another small RCT suggest that 3 weeks' therapy with a hydrocolloid dressing or with a potent corticosteroid cream (0-1% triamcinolone acetonide) is insufficient to induce resolution but that a combination of the two is significantly more effective.16 Hydrocolloid dressings have also been used with the topical vitamin D analogue, calcipotriol. In a small single-blind controlled trial in 15 patients, symmetrical chronic plaques were treated with either calcipotriol ointment or a superpotent corticosteroid ointment (0-05% clobetasol propionate) under hydrocolloid occlusion; dressings were changed every 4 days. Two patients were withdrawn because of irritation by calcipotriol; in the remaining 13 patients all treated plaques had cleared by day 12.17
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Do You Suffer From the Itching and Scaling of Psoriasis? Or the Chronic Agony of Psoriatic Arthritis? If so you are not ALONE! A whopping three percent of the world’s populations suffer from either condition! An incredible 56 million working hours are lost every year by psoriasis sufferers according to the National Psoriasis Foundation.