Psoriasis

Updated: September 2009

What Is Psoriasis?
Fast Facts: An Easy-to-Read Series of Publications for the Public

What Is Psoriasis?

Psoriasis is a skin disease that causes scaling and inflammation (pain, swelling, heat, and redness). Skin cells grow deep in the skin and slowly rise to the surface. This process is called cell turnover, and it takes about a month. With psoriasis, it can happen in just a few days because the cells rise too fast and pile up on the surface.

Most psoriasis causes patches of thick, red skin with silvery scales. These patches can itch or feel sore. They are often found on the elbows, knees, other parts of the legs, scalp, lower back, face, palms, and soles of the feet. But they can show up other places such as fingernails, toenails, genitals, and inside the mouth.

Who Gets Psoriasis?

Anyone can get psoriasis, but it occurs more often in adults. In many cases, there is a family history of psoriasis. Certain genes have been linked to the disease. Men and women get psoriasis at about the same rate.

What Causes Psoriasis?

Psoriasis begins in the immune system, mainly with a type of white blood cell called a T cell. T cells help protect the body against infection and disease. With psoriasis, T cells are put into action by mistake. They become so active that they set off other immune responses. This leads to swelling and fast turnover of skin cells. People with psoriasis may notice that sometimes the skin gets better and sometimes it gets worse. Things that can cause the skin to get worse include:

  • Infections
  • Stress
  • Changes in weather that dry the skin
  • Certain medicines.

How Is Psoriasis Diagnosed?

Psoriasis can be hard to diagnose because it can look like other skin diseases. The doctor might need to look at a small skin sample under a microscope.

How Is Psoriasis Treated?

Treatment depends on:

  • How serious the disease is
  • The size of the psoriasis patches
  • The type of psoriasis
  • How the patient reacts to certain treatments.

All treatments don't work the same for everyone. Doctors may switch treatments if one doesn't work, if there is a bad reaction, or if the treatment stops working.

Topical Treatment:

Treatments applied right on the skin (creams, ointments) may help. These treatments can:

  • Help reduce inflammation and skin cell turnover
  • Suppress the immune system
  • Help the skin peel and unclog pores
  • Soothe the skin.

Light Therapy:

Natural ultraviolet light from the sun and artificial ultraviolet light are used to treat psoriasis. One treatment, called PUVA, uses a combination of a drug that makes skin more sensitive to light and ultraviolet A light.

Systemic Treatment:

If the psoriasis is severe, doctors might prescribe drugs or give medicine through a shot. This is called systemic treatment. Antibiotics are not used to treat psoriasis unless bacteria make the psoriasis worse.

Combination Therapy:

When you combine topical (put on the skin), light, and systemic treatments, you can often use lower doses of each. Combination therapy can also lead to better results.

What Are Some Promising Areas of Psoriasis Research?

Doctors are learning more about psoriasis by studying:

  • Genes
  • New treatments that help skin not react to the immune system
  • The association of psoriasis with other conditions such as obesity, high blood pressure, and diabetes.

For More Information About Psoriasis and Other Related Conditions:

National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Information Clearinghouse
National Institutes of Health

1 AMS Circle
Bethesda, MD 20892-3675
Phone: 301-495-4484
Toll Free: 877-22-NIAMS (877-226-4267)
TTY: 301-565-2966
Fax: 301-718-6366
Email: NIAMSinfo@mail.nih.gov
Website: http://www.niams.nih.gov

The information in this publication was summarized in easy-to-read format from information in a more detailed NIAMS publication. To order the Psoriasis Q&A full-text version, please contact NIAMS using the contact information above. To view the complete text or to order online, visit www.niams.nih.gov.

For Your Information

This publication contains information about medications used to treat the health condition discussed here. When this publication was developed, we included the most up-to-date (accurate) information available. Occasionally, new information on medication is released.

For updates and for any questions about any medications you are taking, please contact

U.S. Food and Drug Administration

Toll Free: 888INFOFDA (8884636332)
Website: http://www.fda.gov

For additional information on specific medications, visit Drugs@FDA at www.accessdata.fda.gov/scripts/cder/drugsatfda. Drugs@FDA is a searchable catalog of FDA-approved drug products.

This publication is not copyrighted. Readers are encouraged to duplicate and distribute as many copies as needed.

Additional copies of this publication are available from:

National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Information Clearinghouse
National Institutes of Health

1 AMS Circle
Bethesda, MD 20892-3675
Phone: 301-495-4484
Toll Free: 877-22-NIAMS (877-226-4267)
TTY: 301-565-2966
Fax: 301-718-6366
Email: NIAMSinfo@mail.nih.gov
Website: http://www.niams.nih.gov

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