Overview
Topical treatments for psoriasis include steroids, tar and anthralin, calcipotriene, tazarotene, and ultraviolet (UV) B light. Topical drugs affect the local area on which they are applied (i.e., the skin surface), while systemic drugs are usually either taken by mouth or injected and affect the entire body.
Detailed Description
Topical steroids
Topical steroids help to decrease the rate of rapidly dividing cells and reduce inflammation in psoriatic plaques. The over-the-counter preparations of hydrocortisone are usually too weak to be effective against psoriasis. Also, the skin on your face is much thinner than the skin on your elbows, so the same strength topical steroids should not be used on these two sites. Your dermatologist can prescribe the appropriate strength and vehicle (cream, ointment, or steroid- impregnated tape) of topical steroid for you.
The skin usually responds to topical steroids in several weeks, but you can build up a tolerance to the drug, which then renders it ineffective. To prevent this, your dermatologist may instruct you to alternate topical steroids with other topical medications for psoriasis such as calcipotriene. A side effect of long-term topical steroid is atrophy, or thinning, of the skin. This can also be prevented by alternating topical steroids with another anti- psoriatic medication.
Tar and anthralin
Tar and anthralin are hydrocarbons that help to decrease the rate of rapidly dividing cells in psoriatic plaques. Tar can also reduce inflammation. Although these products require a longer period of use than topical steroids before a response is seen, their positive effects can be longer lasting. Both tar and anthralin can stain skin and fabrics. Tar oils are often added to a bath to treat the total skin surface. Therapeutic shampoos contain tar as well. Otherwise, tar can be applied to local areas on the skin at bedtime. For people with severe psoriasis involving the trunk, tar can be used in conjunction with ultraviolet (UV) B light, which is called the Goeckerman regimen after the dermatologist who pioneered this treatment. Anthralin is available in a cream preparation in different strengths. It can be irritating, so it is often started at low doses and gradually increased as the patient tolerates. It is often used overnight as well.
Calcipotriene
Calcipotriene (Dovonex) is a Vitamin D derivative that helps to decrease the rate of rapidly dividing cells in psoriatic plaques. It can require several months before a full effect is seen. Because calcipotriene is non-steroidal, it does not cause skin atrophy. Therefore it works well in alternation with topical steroids. In high doses, calcipotriene can increase your body’s calcium levels. Caution should be taken not to apply it to greater than 40% of the body surface.
Tazarotene
Tazarotene is a new topical retinoid that decreases the proliferation of cells. It can be applied at bedtime, followed by a topical steroid in the morning. Tazarotene is rated category X for pregnancy, so it should not be used in women with childbearing potential.
Ultraviolet B (UVB) light
Ultraviolet light at short wavelengths is called UVB. UVB comes naturally from the sun, which may explain why your psoriasis may get better in the summer months. Dermatologists’ offices often have a UVB light box for more controlled exposure to the affected areas of your skin. UVB therapy is often combined with other emollients or with tar. Up to 50% of patients with thin plaques respond well to this therapy. Others may need to use long- wavelength UV light called UVA.
Related Conditions
Psoriasis
Related Procedures
Psoriasis- Systemic treatments
Last updated: 23-Apr-02
