There is no still cure for this disease of the immune system, but there are a number of treatment options that can control its symptoms and even lead to remission. Below, two psoriasis experts discuss effective treatments for this painful skin disorder.
Dr. Gordon, what are the goals of psoriasis treatment?
KENNETH GORDON, MD: The goal is to control the disease to the point where the patient can perform their daily activities in a way that's satisfactory to them. For each patient that level of disease control is going to be different.
Dr. Lebwohl, could you describe the topical treatments for psoriasis?
MARK LEBWOHL, MD: There are dozens, if not hundreds of topical medications, but they fall into a small number of categories. Until recently, the most commonly prescribed treatment for psoriasis was topical corticosteroids, and there are at least 100 of these available worldwide. They range in strength from very weak to very strong. They come in lotions, solutions, creams, emollient creams, and ointments. As a rough rule, the messier they are, the more effective they are, so that ointments are more effective than creams. There are a number of other agents that were more recently developed - such as vitamin D analogs, like calcipotriene, and retinoids, such as tazarotene. There are some old-fashioned treatments as well, which are derived from tar. Tars themselves that are used are anthralin, which is a rather messy treatment that is available for psoriasis.
Do you need a prescription for these topical treatments?
KENNETH GORDON, MD: You are required to have prescriptions for all the topical medication except the weakest topical corticosteroid - which is the hydrocortisone you're able to get over the counter. But as a patient's psoriasis gets more severe, having to apply these creams day in and day out becomes a little bit overwhelming. They're not able to use them consistently, and patients can't comply with the medications. So the use of topical therapy for psoriasis, though effective in many cases, is limited a little bit in patients who have severe cases.
What is phototherapy?
MARK LEBWOHL, MD: There are three forms of phototherapy -- and actually, if you count lasers, now a fourth form. Old-fashioned ultraviolet B has been around for more than 80 years, and is quite effective in a number of psoriasis patients. Usually patients who respond to sunlight will get better with old-fashioned UVB.
There is a newer form of UVB, which is substantially more effective, called narrow band UVB. It hasn't been around as long, so we don't quite know its safety profile, but hopefully it'll be just as safe as old-fashioned UVB.
There is also a form of light treatment called PUVA, in which patients ingest a pill, called a psoralen, and are then exposed to UVA. That is a very effective form of treatment for psoriasis. Unfortunately, it's associated with the development of skin cancers.
And recently, lasers have been shown to be effective for the treatment of psoriasis.
Are these treatments available only in the doctor's office?
KENNETH GORDON, MD: In general, yes. There are current attempts to set up small offices exclusively to offer phototherapy, but in general they're given by a dermatologist.
Who is a good candidate for phototherapy?
KENNETH GORDON, MD: There are a lot of variables. Among these variables is the patient's ability to come in for the treatments. Usually these treatments are between three and five days a week, and a lot of patients who have busy schedules can't do it, though it is a very effective treatment for psoriasis.
Could you talk about the oral medication called methotrexate?
KENNETH GORDON, MD: Methotrexate is a medicine that was first used as a chemotherapy agent in cancer patients, but it can be effective as a treatment for psoriasis as well. It's given once a week in various doses, and patients tend to do pretty well with it. The difficulty with methotrexate is that it can cause toxicities. The foremost concern in most dermatologists' minds is hepatotoxicity, or problems with the liver. Patients using this drug must have a liver biopsy to make sure that they're not developing any form of cirrhosis or hepatic fibrosis. Still, it is an effective therapy. It just needs to be monitored very carefully.
What is cyclosporin, and how is it used in the treatment of psoriasis?
MARK LEBWOHL, MD: Cyclosporin is a potent immunosuppressive agent commonly used to prevent acute transplant rejection. It is used only in severe cases of psoriasis, because it is associated with many side effects. And those patients treated with cyclosporin would have to have failed with safer treatments, such as phototherapy, or perhaps even methotrexate. If a patient tells me that they won't give up their one or two beers a week, which is something we would not allow a methotrexate patient to have, I might consider them for cyclosporin.
A woman who is pregnant and has severe psoriasis would be an ideal candidate for cyclosporin. It is one of the few treatments - aside from phototherapy and UVB phototherapy - that is not contraindicated during pregnancy.
What are vitamin A derivatives, and are they effective?
MARK LEBWOHL, MD: These are called retinoids. The one that is approved for psoriasis currently is acitretin, and there are certainly others on the horizon. They are very effective when used in combination with ultraviolet light -- PUVA or UVB.
Retinoids used by themselves, with no additional therapy, are not very effective for most forms of psoriasis. When retinoids are used by themselves, the doses are associated with significant side effects, such as hair loss, thinning nails, a sticky feeling to the skin, chapped lips, dry skin, and increased fat levels in the blood. Perhaps the most serious side effect is that they cause severe birth defects in the babies of women who become pregnant while taking them, or for a period of time after taking retinoids. So there are a lot of drawbacks to their use, but if they're used intelligently - in very low doses used in combination with phototherapy -- they can be very effective.
Do you ever use these medications together Dr. Gordon?
KENNETH GORDON, MD: At times, yes. There are certain treatments, like combining methotrexate and cyclosporin, where you can, theoretically, decrease the amount used of both drugs, and therefore lessen the potential of side effects associated with each. But I think drug combination therapy has to be reserved for the more severe patients.
When is rotational therapy appropriate?
MARK LEBWOHL, MD: The reason that we rotate therapies is because of the toxicities of each of the treatments. Methotrexate causes liver damage. Cyclosporin probably causes kidney damage in most patients who take it long enough. PUVA causes skin cancers. All of those toxicities are related to the amount of treatment you received. So if you can get a little bit of methotrexate, and before you need a liver biopsy, switch to another treatment, such as cyclosporin, and before you run into kidney trouble, switch to another treatment, you may be able to minimize the toxicity of each of the treatments. That, of course, presupposes that the patient is going to respond to each of the treatments.
