• Definition
    • 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.

  • Alternative Names
    • Plaque psoriasis; Psoriasis vulgaris; Guttate psoriasis; Pustular psoriasis

  • Causes
    • Psoriasis is very common. Anyone can develop it, but it most often begins between ages 15 to 35.

      Psoriasis isn't contagious. This means it doesn't spread to other people.

      Psoriasis seems to be passed down through families. Health care providers 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 in 2 weeks rather than in 3 to 4 weeks. This results in dead skin cells building up on the skin's surface, forming the patches of scales.

      The following may trigger an attack of psoriasis or make it harder to treat:

      • Infections from bacteria or viruses, including strep throat and upper respiratory infections
      • 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)
      • Drinking too much alcohol

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

      Some people with psoriasis also have arthritis (psoriatic arthritis).

  • 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. The medical term for the patches is plaques. Plaques are most often seen on the elbows, knees, and middle of the body. But they can appear anywhere, including on the scalp, palms, and soles of the feet.

      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
      Psoriasis on the knuckles

      There are 5 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. This form seems to be linked to strep infections.
      • 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 pus-filled blisters (pustules) are surrounded by red, irritated skin.
  • Exams and Tests
    • Your provider can usually 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 provider may order x-rays.

  • Treatment
    • 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
      • 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 provider will likely recommend medicines that suppress the immune system's faulty response. These medicines include methotrexate or cyclosporine. Retinoids can also be used.

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

      • Adalimumab (Humira)
      • Etanercept (Enbrel)
      • Infliximab (Remicade)
      • Ustekinumab (Stelara)
      • Secukinumab (Cosentyx)
      • Apremilast (Otezla)
      • Ixekizumab (Taltz)


      Some people may choose to have phototherapy:

      • This is treatment in which your skin is carefully exposed to ultraviolet light.
      • It may be given alone or after you take a drug that makes the skin sensitive to light.
      • Phototherapy for psoriasis can be given as ultraviolet A (UVA) or ultraviolet B (UVB) light.


      If you have an infection, your provider 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 an attack.
      • Oatmeal baths may be soothing and may help to loosen scales. You can use over-the-counter oatmeal bath products. Or, you can mix 1 cup (240 mL) of oatmeal into a tub (bath) of warm water.
      • Keeping your skin clean and moist, and avoiding your specific psoriasis triggers may help reduce the number of flare-ups.
      • Sunlight may help your symptoms go away. Be careful not to get sunburned.
      • Relaxation and anti-stress techniques. The link between stress and flares of psoriasis is not well understood.
      • Limiting the alcoholic beverages you drink may help keep psoriasis from getting worse.
  • Support Groups
  • Outlook (Prognosis)
    • Psoriasis can be a lifelong condition that can be controlled with treatment. It may go away for a long time and then return. With proper treatment, it will not affect your overall health. But be aware that there is a strong link between psoriasis and other health problems, such as heart disease.

  • When to Contact a Medical Professional
    • Call your provider if you have symptoms of psoriasis or if your skin irritation continues despite treatment.

      Tell your provider if you have joint pain or fever with your psoriasis attacks.

      If you have symptoms of arthritis, talk to your dermatologist or rheumatologist.

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

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

  • References
    • Gordon KB, Blauvelt A, Papp KA, et al. Phase 3 Trials of Ixekizumab in Moderate-to-Severe Plaque Psoriasis. N Engl J Med. 2016;375(4):345-356. PMID: 27299809

      Habif TP. Psoriasis and other papulosquamous diseases. In: Habif TP, ed. Clinical Dermatology: A Color Guide to Diagnosis and Therapy. 6th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 8.

      Lebwohl MG, van de Kerkhof PCM. Psoriasis. In: Lebwohl MG, Heymann WR, Berth-Jones J, Coulson I, eds. Treatment of Skin Disease: Comprehensive Therapeutic Strategies. 4th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 203.

      Menter A, Korman NJ, Elmets 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;62(1):114-135. PMID: 19811850