The ideal treatment for psoriasis would clear the disease completely and have no drawbacks. Unfortunately, many of the most effective treatments for psoriasis have unpleasant side effects, are risky when used for long periods or are so new that their long-term safety is unproven. As a result, trying to completely clear psoriasis is not always realistic. A better goal for many people is to see a significant improvement, while keeping side effects to a minimum.
Dermatologists rate the severity of psoriasis using the Psoriasis Area Severity Index (PASI) score. This score takes into account both the size of the area involved and the severity of the lesions. A 75 percent decrease in the PASI score is considered a significant improvement. However, patients may have a different view of what constitutes success. Some people want their skin to be completely clear and view a single dime-sized patch as a problem. For someone else, the goal might be to have arms and legs that are free of the disease so that they can wear short-sleeved shirts and shorts in the summer.
When you consult with a doctor about your psoriasis, it's important to explain how severely psoriasis affects your quality of life, the results you would like to achieve and how comfortable you are with taking a medication that could have long-term side effects. If the doctor understands your priorities, the two of you will be in a better position to design a plan that balances the benefits and risks of treatment.
The next step is to select an appropriate treatment regimen. People with mild psoriasis can usually get good results with topical preparations. Anthralin , tazarotene (Tazorac) and calcipotriol (Dovonex) may produce long-term remission, but only when used continuously. Corticosteroids begin to work quickly, but remission is brief and the medication stops working over time. Another option for people with mild psoriasis is ultraviolet B therapy. Combining this with a coal tar preparation can boost the chance of long-term remission, especially if maintenance treatments are used.
People with moderate-to-severe psoriasis often need to take systemic agents such as acritretin (Soriatane), cyclosporine or methotrexate. Remission can last more than three months with acritetin and fewer than three months with cyclosporine or methotrexate, but all of these agents must be continued in order to maintain remission. This is a problem because methotrexate and cyclosporine have significant side effects when taken over long periods, and acritretin is extremely irritating to the skin. Psoralen plus ultraviolet A (PUVA) treatments can produce even longer remissions. In one study, 40 percent of patients went into remission for a year or longer after a single course of treatment, However, long-term use increases the risk of skin cancer.
The biologic therapies alefacept (Amevive), etanercept (Enbrel) and infliximab (Remicade) all produce extended remission times. Studies of alefacept, for example, have found that remission can last for seven months or more after treatments have ended. Biologic agents appear to be relatively safe, but their long-term risks are unknown. There is a potential risk of serious infection or cancer with these agents.
