Topical steroids: corticosteroids and cortisones Steroids can be applied as ointments, creams, lotions, aerosols or tapes. Thick, plaque-type psoriasis on elbows, knees, palms, soles and other thickly skinned areas tends to resist steroids and requires other topical therapy. Alternatively, lesions in body folds, the groin area, eyelids and other thinly skinned areas are usually more sensitive to steroid treatment. Topical steroids can be used to complement other forms of topical therapy, such as tar and ultraviolet light or tazarotene gel, but they are not meant to replace them. When using topical steroids, apply them sparingly to the skin lesion as a thin film. Strong steroids should not be applied to the face or skin folds. If skin irritation, bruising, ulcers or skin infections occur, stop the treatment immediately and consult your doctor. Some patients see a worsening of their psoriasis after using steroids. Overuse or incorrect use can cause the skin to become very thin. This can sometimes be reversed once the medication has been stopped. Thinning skin is a particular problem with babies and young children as their skin is naturally thin. As a result, long term applications of strong topical steroids in young patients are usually avoided. Other side effects of steroids include acne, rosacea, secondary infections of the skin and dermatitis.
Topical vitamin D treatments
Most patients get improvement with vitamin D treatments such as calcipotriene, calcipotriol and unlike topical corticosteroids, do not cause skin thinning or the sudden worsening of psoriasis that sometimes follows the discontinuation of the topical corticosteroid. Some patients develop skin irritancy around the psoriasis areas and the ointment may also produce a skin rash if applied to the face. It is available in cream, ointment and scalp formulations. Curatoderm ointment is another vitamin D treatment that can be used on the face. These treatments are often effective for plaque like psoriasis. Dovonex scalp solution may be useful in mild types of scalp psoriasis but generally is only partly effective for more chronic or severe scalp psoriasis. They are a safe and frequently effective way of improving psoriasis and can be used for a long period of time, however, irritation can occur, especially on the face, bottom and genitals.
Coal tars seem to be the most effective in controlling psoriasis. Used alone they are not very effective but when used in conjunction with ultraviolet therapy, topical corticosteroids and/or with anthralin spray, they have proven beneficial to combat psoriasis. Unfortunately, using tar can be very messy and can stain both clothing and furnishings.To avoid this, it should be applied at least 15 minutes before dressing or going to bed and wear older clothing. You will need to avoid exposing coal tar treated areas of the skin to the sun as it increases the risk of sunburn. Recently, some coal tar containing shampoos have been removed by the US authorities because of fears of increased skin cancer risk. Dithranol is a synthetic substance made from anthracene, a coal tar derivative. It takes longer to work than steroids, in many cases up to 6 weeks. It can also irritate the skin and stain everything it touches including normal skin. Skin staining is a sign that the dithranol is working. As it does not stain psoriatic skin, the staining means that the skin is clearing up. The stain should clear up a few weeks after the psoriasis itself has cleared. Dithranol is applied only to the psoriatic lesions and must be rubbed in well. Any excess should be wiped off. It must not be applied to the face or groin. It works but is a messy and often cosmetically troubling treatment.
Emollients commonly used in cream or lotion form are an important component of psoriasis therapy. They seem to slow the loss of water through the skin layers that result from frequent bathing and phototherapy sessions. The thicker the cream or lotion, the more effective the emollient is likely to be. Regular effective moisturisation can relieve the pain of dry skin and also reduce scaling and inflammation. In addition they have no side effects to worry about.