Psoriasis: More than Skin Deep

Jennifer Wider, M.D.
Society for Women’s Health Research
August 21, 2008

Psoriasis is a chronic disease of the immune system that affects the skin. As many as 7.5 million Americans suffer from psoriasis, according to the National Institutes of Health. Unlike other diseases of the immune system which affect women more often than men, psoriasis occurs about equally in men and women.

Psoriasis is not contagious and cannot be spread from person to person. There are five known forms of the disease. “The most common form, plaque psoriasis, appears as raised, red patches or lesions covered with a silvery white buildup of dead skin cells called scale,” explains Bruce F. Bebo, Jr., Ph.D., director of research and medical programs at the National Psoriasis Foundation in Portland, Ore.

For some people, psoriasis can be a nuisance, for others, it can be debilitating. The symptoms vary from person to person and can include:

• Red, itchy patches of skin that are covered with silver-colored scales.
  
  
• Dry, irritated or cracked skin that can bleed when scratched.
  
  
• Disorders of the fingernails or toenails including thickened or ridged nails. The nails can become brittle and in some cases, detach from the nail beds.

Most cases of psoriasis wax and wane and include flare-ups which last for a few weeks to months.  Some people will go into remission for months to years. But in most cases, the psoriasis will reappear.
Psoriasis can also lead to psoriatic arthritis, which can cause pain and swelling in the joints. Roughly one-tenth to one-third of people with psoriasis will also have psoriatic arthritis, according to the National Psoriasis Foundation. Psoriatic arthritis can lead to joint erosion and get in the way of daily functioning. 

Although it affects both genders equally, recent studies show that there may be a racial or ethnic link.  “It seems that psoriasis is most common in Caucasians and slightly less common in African Americans. Worldwide, psoriasis is most common in Scandinavia and other parts of northern Europe. It appears to be far less common among Asians and is rare in Native Americans,” Bebo points out. 

Research has identified some differences between the sexes in psoriasis related to smoking and alcohol consumption.

Smoking increases the risk of developing psoriasis and can make the disease more severe, especially in women, but the risk goes down if you stop smoking. Alcohol appears to affect psoriasis in men more strongly than in women. Researchers don’t know why, but alcohol consumption appears to be a risk factor for psoriasis in men but not women and it may lower treatment response in men.

The cause of psoriasis isn’t fully clear. The disease is related to a malfunction in the immune system, which results in T-cells attacking healthy skin cells. What triggers the T-cell malfunction isn’t known, but many researchers cite genetic and environmental factors as possibilities. The most noteworthy risk factor for psoriasis is family history. Roughly 30 percent of people with psoriasis have a close relative with the disease.

Diagnosing psoriasis is often done in a doctor’s office. “No special blood tests or diagnostic tools exist to diagnose psoriasis. The physician or other health care provider usually examines the affected skin and decides if it is from psoriasis. Less often, the physician examines a piece of skin (biopsy) under the microscope,” explains Bebo.

There are several therapies for psoriasis available to patients, which focus on reducing skin inflammation and plaque formation. Looking to the future, there are “a number of new treatments in the psoriasis pipeline,” Bebo said, which may help reduce the burden of this chronic and disabling disease. The types of treatments in development include biologics, monoclonal antibodies and immune system modulators.

Women with psoriasis who are pregnant, may become pregnant, or are breastfeeding should discuss carefully with their doctors their treatment options, as some treatments for psoriasis may cause birth defects. There is, however, some good news for pregnant women. Research has shown that hormonal changes during pregnancy may lead to improvements in psoriasis symptoms, providing temporary relief.

August is Psoriasis Awareness Month. For more information, you can visit the National Psoriasis Foundation online at http://www.psoriasis.org/.

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© August 21, 2008 Society for Women's Health Research