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FRIDAY, Aug. 15, 2003 (HealthDayNews) -- For the nearly 5 million Americans who suffer from psoriasis, life can be a painful odyssey of pills, creams and even light therapy. Worse yet, the condition can spread beyond large swaths of skin to the joints, leading to debilitating arthritis.
To get the word out about this potentially disabling disorder, the National Psoriasis Foundation has designated August as Psoriasis Awareness Month.
Fortunately, knowledge about the condition is increasing and, with it, the stock of available remedies. The most promising are new biologic treatments that work with few side effects, experts say.
"I'd say [psoriasis] is very treatable. It's just not curable," says Dr. Ted Daly, director of pediatric dermatology at Nassau University Medical Center in East Meadow, N.Y.
Psoriasis is immune-mediated, meaning that abnormal immune system responses are somehow involved.
"There's no question that the immune system plays a role in the development of the disease," says Dr. Mark Lebwohl, professor and chairman of the department of dermatology at the Mount Sinai School of Medicine in New York City and president of the medical board of the Psoriasis Foundation.
Other than that, no one is sure what causes the disease, although there does seem to be a genetic component. "We have not identified the psoriasis gene, but [the disease] seems to be a combination of genes and external factors," Lebwohl says.
While the precise causes are unclear, some triggers have been identified, including strep throat, cold weather, being out of the sun and even the drug lithium, which is commonly prescribed for bipolar disorder.
What is certain, however, is the suffering it can cause. Psoriasis manifests as an uncomfortable itchy, thickening of the skin with red patches and silvery scales. These abnormal patches are really areas of extra skin cells. Inside the body, defective immune systems trigger a series of events that lead to the skin's outer layer growing at a much faster rate than normal.
"Instead of being a month, the turnover of cells happens within a week or even less," Daly explains. There's not enough time for the dead cells to slough off, so these buildups occur. The red comes from the excess blood supply needed by the rapidly growing cells.
For some people, the rash is confined to a small part of the body, such as elbows, knees or scalp. Others aren't so lucky. The scaly area can spread to cover a much greater area. "It can go from a patch or two to 100 percent of the body," Daly says.
And the disease can strike at any age. "Just because you don't have it now doesn't mean you won't get it in the future," Lebwohl explains. "It can come as early as birth and as late as 100 years of age."
Luckily, recent treatment advances are making life easier for many sufferers.
Most exciting is the development of biologic treatments. "These drugs target specific receptors on molecules or specific chemicals without affecting the entire immune system," Lebwohl says. That means they have far fewer side effects than conventional treatments.
The U.S. Food and Drug Administration (FDA) approved the first biologic treatment for psoriasis in March: alefacept (brand name Amevive). A study published in the June issue of the Archives of Dermatology found that people taking 15 milligrams of the drug had a 75 percent reduction in their Psoriasis Area and Severity Index (PASI), a measure of the severity of the condition. Alefacept stops the overproduction of skin cells by destroying the defective immune cells that are responsible for the abnormality.
"That's one of at least five new agents that are in development for psoriasis and probably more will be coming after that and probably we haven't even seen the best of them," Lebwohl says. "As time goes on, we're going to see better and better molecules."
Enbrel, or etanercept, another biologic agent, was approved for psoriatic arthritis in January 2002 and is currently being considered by the FDA for moderate to severe psoriasis.
Many patients still rely on the traditional arsenal of treatments, many of which have been around for decades. "Those treatments are still very useful," Lebwohl says.
Some, such as cyclosporine, may be more effective than the biologics, but can entail severe side effects. Cyclosporine can damage the kidneys, and methotrexate, a chemotherapy drug, can cause liver damage. Both of these drugs are for more severe forms of the disease, doctors say.
A variety of treatments are available for milder versions of psoriasis, including creams you put directly on your skin (for instance, steroid creams and topical vitamin D). People with larger affected areas might benefit from light therapy, or even a combination of this and topical creams.
More information
For more on psoriasis, visit the National Institute of Arthritis and Musculoskeletal and Skin Diseases or the National Psoriasis Foundation.
