Psoriasis

Treatments applied directly to the skin may improve its condition. Doctors find that some patients respond well to ointment or cream forms of corticosteroids, vitamin D3, retinoids, coal tar, or anthralin. Bath solutions and moisturizers may be soothing, but they are seldom strong enough to improve the condition of the skin. Therefore, they usually are combined with stronger remedies.

• Corticosteroids--These drugs reduce inflammation and the turnover of skin cells, and they suppress the immune system. Available in different strengths, topical corticosteroids (cortisone) are usually applied to the skin twice a day. Short-term treatment is often effective in improving, but not completely eliminating, psoriasis. Long-term use or overuse of highly potent (strong) corticosteroids can cause thinning of the skin, internal side effects, and resistance to the treatment's benefits.

• Calcipotriene--This drug is a synthetic form of vitamin D3 that can be applied to the skin. Applying calcipotriene ointment (for example, Dovonex*) twice a day controls the speed of turnover of skin cells. Because calcipotriene can irritate the skin, however, it is not recommended for use on the face or genitals. It is sometimes combined with topical corticosteroids to reduce irritation. Use of more than 100 grams of calcipotriene per week may raise the amount of calcium in the body to unhealthy levels.

• Retinoid--Topical retinoids are synthetic forms of vitamin A. The retinoid tazarotene (Tazorac) is available as a gel or cream that is applied to the skin. If used alone, this preparation does not act as quickly as topical corticosteroids, but it does not cause thinning of the skin or other side effects associated with steroids. However, it can irritate the skin, particularly in skin folds and the normal skin surrounding a patch of psoriasis.

• Coal tar--Preparations containing coal tar (gels and ointments) may be applied directly to the skin, added (as a liquid) to the bath, or used on the scalp as a shampoo. Coal tar products are available in different strengths, and many are sold over the counter (not requiring a prescription).

• Anthralin--Anthralin reduces the increase in skin cells and inflammation. Doctors sometimes prescribe a 15- to 30-minute application of anthralin ointment, cream, or paste once each day to treat chronic psoriasis lesions. Afterward, anthralin must be washed off the skin to prevent irritation.

• Salicylic acid--This peeling agent, which is available in many forms such as ointments, creams, gels, and shampoos, can be applied to reduce scaling of the skin or scalp. Often, it is more effective when combined with topical corticosteroids, anthralin, or coal tar.

• Clobetasol propionate--This is a foam topical medication (Olux), which has been approved for the treatment of scalp and body psoriasis. The foam penetrates the skin very well, is easy to use, and is not as messy as many other topical medications.

• Bath solutions--People with psoriasis may find that adding oil when bathing, then applying a moisturizer, soothes their skin. Also, individuals can remove scales and reduce itching by soaking for 15 minutes in water containing a coal tar solution, oiled oatmeal, Epsom salts, or Dead Sea salts.

• Moisturizers--When applied regularly over a long period, moisturizers have a soothing effect. Preparations that are thick and greasy usually work best because they seal water in the skin, reducing scaling and itching.