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What is Psoriasis?

Psoriasis is a complex, chronic, recurring skin disease that affects 1%-3% of the population worldwide. It often develops during young adulthood but can occur at any age. The most common type (plaque psoriasis) appears as round, red, dry “plaques” covered with silvery white scales. These plaques can itch, burn and be painful. Psoriasis can appear on any part of the body but usually involves the scalp, knees, elbows, and torso. It also can appear on hands, fingernails, feet, face, armpits, groin, and even in the mouth.

Psoriasis is an autoimmune disease, which means that the immune system attacks a person’s body in addition to attacking bacteria, viruses and other invading pathogens.[de Rie et al., 2004] Psoriasis appears to be inherited due to multiple genetic factors.[Bowcock AM, 2005] It is most common in Caucasian populations, appearing in similar numbers of men and women. Psoriasis is ranked as mild, moderate or severe based on the amount of skin affected. Almost one-third of patients have moderate level of psoriasis. If the affected skin is readily visible (such as facial plaques), significant, painful, or affects everyday function (such as hands and feet), psoriasis can dramatically decrease a person’s quality of life.[Muktar et al., 2004] Some patients with psoriasis also develop psoriatic arthritis, a related autoimmune condition marked by joint stiffness and swelling .[de Rie et al., 2004]

There are five types of psoriasis: 1) plaque, 2) guttate, 3) inverse, 4) pustular, and 5) erythrodermic.[de Rie et al., 2004]

Plaque psoriasis is the most common type of psoriasis. It is associated with skin sores about 1/8-inch in diameter or larger. It often involves the scalp, elbows, and knees, but it can also involve other locations.

Guttate psoriasis is associated with smaller plaques, which occur on the trunk and limbs. It is most common in children and young adults. Sometimes it can resolve, reappear, or transform into plaque psoriasis.

Inverse psoriasis appears in the groin area, armpits, and skin folds. Affected skin is usually red and shiny, rather than dry and scaly. Affected skin is easily irritated because of its location.

Pustular psoriasis is unusual. Affected skin develops white or yellow blisters with red plaques. It also can be scaly. Pustular psoriasis may be limited to certain areas of the body such as the hands or feet.

Erythrodermic psoriasis appears as a widespread eruption of red, inflamed skin. Skin can shed, itch, and be very painful. Because the entire body is often involved, patients may be unable to maintain normal fluid levels or temperature. Although uncommon, severe forms of erythrodermic psoriasis can be life-threatening.

There is no specific test for psoriasis. Our health care providers will diagnose psoriasis based on your symptoms, and medical history. Skin samples may be examined under a microscope, or a biopsy may be needed. Our health care providers may also perform other tests to rule out skin diseases that have similar symptoms.

As of yet, there is no cure for psoriasis. Treatments are designed to help relieve symptoms and to reduce the severity and frequency of recurrences. Treatment also varies with the type of psoriasis, its severity, and the body area affected. For mild to moderate psoriasis, your physician may prescribe a mix of topical corticosteriods, vitamin D analogs, coal tar, or salicylic acid.[Lebwohl et al., 2005; Callen et al., 2003] For moderate cases, phototherapy, with or without photosensitizers, may be prescribed.[Lebwohl et al., 2005; Callen et al., 2003; Zanolli M, 2003]

In moderate or severe cases that fail to respond to topical therapies, our health care providers may consider prescribing orally administered drugs.[Lebwohl et al., 2004] Examples include immunosuppressant drugs like cyclosporine and synthetic vitamin A analog sand antimetabolites such as methotrexate. Newer treatment options include injectable biologics, such as alefacept and efalizumab, which are designed to block abnormal immune system activation.[ Callen et al., 2003]

Psoriasis can be managed by keeping the skin moist through the use of moisturizing lotions and creams. Because psoriasis is an autoimmune condition, reducing the stress in your life may reduce the severity or frequency of recurrences. Talk to our health care providers before making major changes to your diet or before taking dietary supplements used in some alternative therapies.

Regular exposure to sunlight may help manage psoriasis, similar to the effects of phototherapy. Be sure to use sunscreen on unaffected skin and to wear protective sunglasses.

Learn about psoriasis from local and national support organizations such as the National Psoriasis Foundation ( When outbreaks occur, carefully follow the instructions given to you by our health care providers for skin care and medication use.

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