Topical psoriasis treatment includes corticosteroids, calcipotriol/calcipotriene, tazarotene, tars, and anthralin. Tars and anthralin are discussed above.
Calcipotriol and Betamethasone Dipropionate (Dovobet®)
Calcipotriol is safe and an effective treatment for psoriasis when used along but the onset of action is slower than that of topical corticosteroids. Skin irritation may also limit its use for some patients. Topical steroids are effective for the treatment of psoriasis by reducing the inflammatory process. The risk of side effects increases with increasing potency of the steroid as well as the duration of their use.
Combining both corticosteroid and calcipotriol has been shown to be effective. However, extemporaneous compounding of these products is a problem because of stability issues. Calcipotriol needs a basic pH environment whereas betamethasone dipropionate requires an acidic medium. A new vehicle was created in order to satisfy the needs of both of these molecules. This combination product is available in Canada as Dovobet®.
Studies show that Dovobet® is more effective than calcipotriol or betamethasone dipropionate alone. In one clinical trial, after 1 week of treatment, the percentage of reductions in PASI scores were 28% in the calcipotriol trial group, 44% in the betamethasone group and 48% in the Dovobet® group.
Dovobet® is as effective when used once daily compared with twice daily. In addition to the adverse effects which may be seen with calcipotriol and topical corticosteroids, Dovobet® is known to cause itching at the site of application. The itching is usually mild with no need to stop treatment. For patients that have been prescribed Dovonex* or Dovobet®, you can access more product information by clicking either of these links and entering the DIN Number from your prescription: www.dovobet.ca or www.dovonex.ca.
Topical Calcipotriol/Calcipotriene (Dovonex®):
Calcipotriol/calcipotriene is a derivative of vitamin D, and it is available in a cream, ointment, and scalp solution. The mechanism of action is unknown, but it is known to slow the excessive turnover of epidermal cells, by influencing keratinocyte differentiation.
The improvement usually starts within 2-3 weeks. The full effect may require up to 2 months. This is effective in a large number of psoriatic with mild to moderate disease. The full effect may require up to 2 months. It is usually effective and safe for long term use. Calcipotriol is an effective treatment in a large number of psoriatic patients with mild to moderate disease. There is a risk of hypercalcaemia if calcipotriol is used extensively, but at dosages of less than 100 gm per week calcium metabolism is not affected. Since it may cause irritation, calcipotriol is not usually used on the face, genitals, or in skin folds.
This can be used in combination with other topical agents as well as photo therapy, (PUVA or UVB) and systemic therapies such as cyclosporine A or acitretin. The use of calcipotriol in combination with other treatments (i.e. topical steroids, cyclosporin, acitretin, PUVA phototherapy or UVB phototherapy) improves efficacy allowing for dosage reduction of the other treatments. However, since the stability of calcipotriol in its marketed formulations may be affected by other compounds, mixtures of calcipotriol and other topical agents should not be prepared.
Anthralin (Dithranol®):
This is derived from chrysarobin, from the bark of the Araroba tree. Anthralin is available as a cream, ointment, and scalp lotion. Lower concentrations can be left on overnight, while stronger ones (1% or higher) should be left on for 15-30 minutes. It is used to treat plaque and guttate psoriasis. Short contact with a high concentration works better than longer contact with a low concentration.
Anthralin slows down the growth of the skin cells and has anti-inflammatory actions. Anthralin can cause staining (purple/brown color) of your clothes, skin, and hair, which limits its use, irritation may also occur, but this can be minimized by applying the anthralin only to the psoriasis patches and avoiding uninvolved skin. You should not use anthralin on the face, genitals, or in the skin folds.
In hospital, administration of anthralin often will clear psoriasis within 2 weeks. Short contact anthralin is effective in a large number of individuals with mild to moderate psoriasis.
In hospital and Day Care Ingram regime involves anthralin paste, coal tar baths as well as ultraviolet light. Short contact anthralin can be administered at home and is good for localized areas of psoriasis. It may be used in combination with both UVB and PUVA.
A product developed in Sweden called Micanol® is designed for short contact use. The anthralin does not stain if it is washed off with cool water.
The mechanism of action is unknown. They may effect expression of genes for cytokines and cell adhesion molecules.
Dithrocreme® 0.1%, 0.25%, 0.5%
DithrocremeHP® 1%
Dithroscalp® 0,25% 0,5%
Micanol® 1%
Topical Corticosteroids (Diprosone®, Valisone®):
Topical steroids are the most commonly prescribed psoriasis medications and they are available as creams, ointments, gels, lotions, solutions, oils, and shampoos. They can be used anywhere on the body and work quite quickly, often within 1-2 weeks. However, with long term use, steroids often lose their effectiveness.
Usually you won't have any side effects with short term use. However, longer use particularly with stronger preparations, may cause thinning of the skin, stretch marks, dilated blood vessels, rosacea, perioral dermatitis, bruising, and hair growth. Progression to a more active form of psoriasis for example, pustular or erythrodermic psoriasis, increased susceptibility to infections, and a flare up of the psoriasis when the medication is stopped.
Topical corticosteroids can be absorbed into the blood circulation and cause a number of side effects in your body, particularly if you are treating large areas and/or using strong steroids. Only mild steroids should be used on the more sensitive skin, such as your face, and in skin folds. Stronger steroids are usually required elsewhere. Pulsed betamethasone diproprionate used three times, 12 hours apart is shown to be useful in maintaining psoriasis. This regimen is suitable for weekend use while non-cortisone can be used during the weekdays.
Topical Tazarotene (Tazorac®):
Tazarotene is a selective retinoid with properties that are similar to vitamin A. Tazarotene is available as a cream and gel. It is effective in the treatment of psoriasis, acne, and photoaging. In the treatment of psoriasis, it may be used by itself, or in combination with a corticosteroid cream or ointment, calcipotriol/calcipotriene or light treatment (UVB, PUVA).
Irritation is common with tazarotene, but you can minimize this by applying a thin layer of the medication only to the patches and avoiding the uninvolved surrounding skin and/or protecting the surrounding skin with petrolatum. You should not use tazarotene on the genitals or in the skin folds. You should not use this medication if you are pregnant.
The mechanism of action is unknown. It may induce growth suppressor genes in keratinocytes. The efficacy is usually slow and starts with reduction of plaque thickness and some improvement in redness and scaling usually occurs after 3 months.
Side effects include redness and burning. It should not be used in women who wish to become pregnant.
Application is usually used daily.
(GCS)
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