Psoriasis: NWHIC

Article title: Psoriasis: NWHIC

Conditions: Psoriasis

Source: NWHIC

PSORIASIS

What is psoriasis?
What causes psoriasis?
Is psoriasis inherited?
How would I know if I had psoriasis?
Is there effective treatment for psoriasis?

What is psoriasis?

Psoriasis is a chronic (long-lasting) skin disease characterized by scaling and inflammation. Scaling occurs when cells in the outer layer of skin reproduce faster than normal and pile up on the skin's surface.

Psoriasis affects 1.5 to 2 percent of the United States population, or almost 5 million people. It occurs in all age groups and about equally in men and women. People with psoriasis may suffer discomfort, restricted motion of joints, and emotional distress.

When psoriasis develops, patches of skin thicken, redden, and become covered with silvery scales. These patches are sometimes referred to as plaques. They may itch or burn. The skin at joints may crack. Psoriasis most often occurs on the elbows, knees, scalp, lower back, face, palms, and soles of the feet. The disease also may affect the fingernails, toenails, and the soft tissues inside the mouth and genitaliAbout 10 percent of people with psoriasis have joint inflammation that produces symptoms of arthritis. This condition is called psoriatic arthritis.

What causes psoriasis?

Recent research indicates that psoriasis may be a disorder of the immune system. The immune system includes a type of white blood cell, called a T cell, that normally helps protect the body against infection and disease. Scientists now think that in psoriasis, an abnormal immune system produces too many T cells in the skin. These T cells trigger the inflammation and excessive skin cell reproduction seen in people with psoriasis.

People with psoriasis may notice that there are times when their skin worsen, then improves. Conditions that may cause flare-ups include changes in climate, infections, stress, and dry skin. Also, certain medicines, such as the nonsteroidal anti-inflammatory drug indomethacin and medicines used to treat high blood pressure or depression, may trigger an outbreak or worsen the disease.

Is psoriasis inherited?

In some cases, psoriasis is inherited. Researchers are studying large families affected by psoriasis to identify a gene or genes associated with the disease. (Genes govern every body function and determine inherited traits passed from parent to child.)

How would I know if I had psoriasis?

Doctors usually diagnose psoriasis after a careful examination of the skin. However, diagnosis may be difficult because psoriasis often looks like other skin diseases. A pathologist may assist with diagnosis by examining a small skin sample under a microscope.

There are several forms of psoriasis. The most common form is plaque psoriasis (its scientific name is psoriasis vulgaris). In plaque psoriasis, lesions have a reddened base covered by silvery scales. Other forms of psoriasis include:

Guttate Psoriasis: Drop-like lesions appear on the trunk, limbs, and scalp. Guttate psoriasis may be triggered by viral respiratory infections or certain bacterial (streptococcal) infections.

Pustular Psoriasis: Blisters of noninfectious pus appear on the skin. Attacks of pustular psoriasis may be triggered by medications, sunlight, infections, pregnancy, perspiration, emotional stress, or exposure to certain chemicals.

Inverse Psoriasis: Large, dry, smooth, vividly red plaques occur in the folds of skin near the genitals, under the breasts, or in the armpits. Inverse psoriasis is related to increased sensitivity to friction and sweating.

Erythrodermic Psoriasis: Widespread reddening and scaling of the skin is often accompanied by itching or pain. Erythrodermic psoriasis may be precipitated by severe sunburn, use of oral steroids (such as cortisone), or a drug-related rash.

Is there effective treatment for psoriasis?

Doctors generally treat psoriasis in steps according to the severity of the disease or responsiveness to initial treatments. This is sometimes called the "1-2-3" approach. In step 1, medicines are applied to the skin (topical treatment). Step 2 involves treatments with light (phototherapy). Step 3 involves taking medicines internally, usually by mouth (systemic treatment).

Over time, affected skin tends to resist some treatments. Also, a treatment that works like magic in one person may have little effect in another. Thus, doctors commonly use a trial and error approach to find a treatment that works, then switch treatments every 12 to 24 months to reduce resistance and adverse reactions. Selection of treatment depends on the location of lesions, their size, the amount of the skin affected, previous response to treatment, and a patient's perceptions about their skin condition and patient preferences for treatment. In addition, treatment is often tailored to the specific form of the disorder.

Treatments can include:

Topical Treatment:sunlight, steroid ointments, medicines made from vitamin D3, coal tar, or anthralin. Other topical measures, such as bath solutions and moisturizers, may be soothing but are seldom strong enough to clear lesions for a sustained length of time and may need to be combined with more potent remedies.

Phototherapy: UVB Phototherapy, PUVA -

Systemic Treatment: Doctors sometimes prescribe medicines that are taken internally for more severe forms of psoriasis, particularly when more than 10 percent of the body is involved.

For More Information...

American Academy of Dermatology

National Psoriasis Foundation 800-723-9166

National Arthritis and Musculoskeletal and Skin Diseases Information

Psoriasis Research Association
107 Vista Del Grande
San Carlos, CA 94070
415-593-1394

This information was abstracted from the Psoriasis Fact sheet of the National Institute of Arthritis and Musculoskeletal and Skin Diseases.

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Publication date: 1998