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Psoriasis is a skin condition that causes skin redness and irritation. Most people with psoriasis have thick, red skin with flaky, silver-white patches called scales.

Causes of Psoriasis

Psoriasis is very common. Anyone can get it, but it most often begins between ages 15 and 35.

Psoriasis is not contagious. You cannot get it from another person or spread it to others.

Psoriasis seems to be passed down through families. Doctors think it may be an autoimmune condition. This occurs when the immune system mistakenly attacks and inflames or destroys healthy body tissue.

Normal skin cells grow deep in the skin and rise to the surface about once a month. When you have psoriasis, this process takes place too fast. Dead skin cells build up on the skin's surface.

These conditions may trigger an attack of psoriasis or make the condition harder to treat:

  • Bacterial or viral infections, including strep throat and upper respiratory infections (such as a cold)
  • Dry air or dry skin
  • Injury to the skin, including cuts, burns, and insect bites
  • Some medicines, including antimalaria drugs, beta-blockers, and lithium
  • Stress
  • Too little sunlight
  • Too much sunlight (sunburn)
  • Too much alcohol

Psoriasis may be worse in people who have a weak immune system. This may be due to:

Some people with psoriasis may also have arthritis. This is called psoriatic arthritis.

Psoriasis Symptoms

Psoriasis can appear suddenly or slowly. Many times, it goes away and then comes back.

The main symptom of the condition is irritated, red, flaky patches of skin. These patches appear most often on the elbows, knees, and middle of the body. But they can appear anywhere, including on the scalp.

The skin may be:

  • Itchy
  • Dry and covered with silver, flaky skin (scales)
  • Pink-red in color (like the color of salmon)
  • Raised and thick

Other symptoms may include:

  • Genital sores in males
  • Joint pain or aching
  • Nail changes, including thick nails, yellow-brown nails, dents in the nail, and a lifting of the nail from the skin underneath
  • Severe dandruff on the scalp

There are five main types of psoriasis:

  • Erythrodermic -- The skin redness is very intense and covers a large area.
  • Guttate -- Small, pink-red spots appear on the skin.
  • Inverse -- Skin redness and irritation occur in the armpits, groin, and in between overlapping skin.
  • Plaque -- Thick, red patches of skin are covered by flaky, silver-white scales. This is the most common type of psoriasis.
  • Pustular -- White blisters are surrounded by red, irritated skin.

Tests and Exams

Very often your health care provider can diagnose this condition by looking at your skin.

Sometimes, a skin biopsy is done to rule out other possible conditions. If you have joint pain, your doctor may order x-rays.

Treatment of Psoriasis

The goal of treatment is to control your symptoms and prevent infection.

Three treatment options are available:

  • Skin lotions, ointments, creams, and shampoos. These are called topical treatments.
  • Pills or injections that affect the body's immune response, not just the skin. These are called systemic, or body-wide, treatments.
  • Phototherapy, which uses ultraviolet light to treat psoriasis.


Most of the time, psoriasis is treated with medicines that are placed directly on the skin or scalp. These may include:

  • Cortisone creams and ointments
  • Creams or ointments that contain coal tar or anthralin (an anti-inflammatory drug)
  • Creams to remove the scaling (usually salicylic acid or lactic acid)
  • Dandruff shampoos (over-the-counter or prescription)
  • Moisturizers
  • Prescription medicines containing vitamin D or vitamin A (retinoids)


If you have very severe psoriasis, your doctor will likely recommend medicines that suppress the immune system's faulty response. These medicines include methotrexate or cyclosporine. Retinoids can also be used, but these work differently from medicines that suppress the immune system.

Newer drugs called biologics are used when other treatments do not work. Biologics approved for the treatment of psoriasis include:


Some people may choose to have phototherapy. This treatment:

  • Carefully exposes your skin to ultraviolet light
  • May be given alone or after you take a drug that makes the skin sensitive to light
  • Can be given as ultraviolet A (UVA) or ultraviolet B (UVB) light


If you have an infection, your doctor will prescribe antibiotics.


Following these tips at home may help:

  • Taking a daily bath or shower. Try not to scrub too hard because this can irritate the skin and trigger a flare-up.
  • Soaking in an oatmeal bath. This may be soothing and may help loosen scales. You can use over-the-counter oatmeal bath products. Or, you can mix 1 cup of plain oatmeal into a tub of warm water.
  • Keeping your skin clean and moist, and avoiding your specific psoriasis triggers. This may help reduce the number of flare-ups.
  • Exposing your skin to sunlight. This may help your symptoms go away, but be careful not to get sunburned.
  • Using relaxation and anti-stress techniques. The link between stress and flare-ups of psoriasis is not well understood, however.
  • Limiting alcoholic beverages. This may help keep psoriasis from getting worse.

Support Groups

Some people may benefit from a psoriasis support group.

Prognosis (Outlook)

Psoriasis can be a life-long condition that can be controlled with treatment. It may go away for a long time and then return. Sometimes it goes away and never returns. With proper treatment it will not affect your overall health.

When to Contact a Health Professional

Call your health care provider if you have symptoms of psoriasis or if your skin irritation continues despite treatment.

Tell your doctor if you have joint pain or fever with your psoriasis attacks. If you have psoriatic arthritis with symptoms of arthritis (such as painful, stiff, or swollen joints), talk to the provider who is treating your psoriasis.

Go to the emergency room or call the local emergency number (such as 911) if you have a severe outbreak that covers all or most of your body.

Prevention of Psoriasis

There is no known way to prevent psoriasis. Keeping your skin clean and moist and avoiding your specific psoriasis triggers may help reduce the number of flare-ups.

Health care providers recommend daily baths or showers for people with psoriasis. Avoid scrubbing too hard, because this can irritate the skin and trigger an attack.


Menter A, Gottlieb A, Feldman SR, Voorhees ASV, Leonardi CL, Gordon KB, et al. Guidelines for the management of psoriasis and psoriatic arthritis. Section 1. Overview of psoriasis and guidelines of care for the treatment of psoriasis with biologics. J Am Acad Dermatol. 2008;5:826-850.

Menter A, Korman NJ, Elmets CA, Feldman SR, Gelfand JM, Gordon KB, et al. American Academy of Dermatology guidelines of care for the management of psoriasis and psoriatic arthritis. Section 3. Guidelines of care for the management and treatment of psoriasis with topical therapies. J Am Acad Dermatol. 2009;60:643-659.

Menter A, Korman NJ, Elments CA, et al. Guidelines of care for the management of psoriasis and psoriatic arthritis.Section 5. Guidelines of care for the treatment of psoriasis with phototherapy and photochemotherapy. J Am Acad Dermatol. 2011;1:114-135. Available at:

Psoriasis. Alvero R, Ferri FF, Fort GG, et al, eds. In: Ferri's Clinical Advisor 2015. 1st ed. Philadelphia, PA: Elsevier Mosby; 2014:section I.

Stern RS. Psoralen and ultraviolet a light therapy for psoriasis. N Engl J Med. 2007;357(7):682-690. Available at:

Weigle N, McBane S. Psoriasis. Am Fam Physician. 2013:87(9);626-633.

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Review Date: 11/12/2014
Reviewed By: Richard J. Moskowitz, MD, dermatologist in private practice, Mineola, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
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