Psoriasis

52228 38 Information for
caption goes here...

Images of Psoriasis

Overview

Psoriasis is a disorder that affects both the skin and the joints, causing a characteristic rash and sometimes arthritis-like joint pain. The rash is usually red and raised, and the skin has a tendency to turn silvery and flaky on top of the red raised areas. Psoriasis can occur on any part of the body, including the scalp and nails. Approximately half of people who have the rash of psoriasis have fingernail changes, and a quarter have joint difficulties. Psoriasis tends to run in families (be hereditary) and is related to problems with the immune system. Psoriasis flares are triggered by many things, some of which are poorly understood; some scientists believe that viruses, injury to the skin (trauma), Streptococcus infection, stress, smoking, and alcohol can all trigger flares. There are no certain cures for psoriasis, but there are treatments that your doctor can prescribe that may help you manage the condition.

Who's at risk?

Psoriasis is common; approximately 1 or 2 in 100 people in the US are affected. It can be seen in anyone of any age but is very rare in infants and more common in teens and adults. Psoriasis is also more common in whites than African Americans. Psoriasis affects men and women fairly equally, with women tending to start showing signs at a younger age than men.

Signs and Symptoms

Psoriasis typically affects the elbows, knees, buttocks, scalp, and genitals; areas of rubbing or friction are particularly likely to develop lesions.

Red or salmon-red, raised areas often have silvery-white or grayish-white scale. Moist areas (such as body folds) may not be scaly.

People with related arthritis may have swelling and pain in the joints (often fingers or toes) or tendons.

The nails may be affected in psoriasis, causing pitting, "oil spots" (yellowish-brown discoloration of nail plate), and lifting of the nail plate from the nail bed (onycholysis).

Psoriasis can be graded as:

  • Mild – Few, scattered, small areas of involvement
  • Moderate – More widespread disease affecting larger areas, sometimes affecting the joints
  • Severe – Most of the skin surface is affected, sometimes affecting the joints

Self-Care Guidelines

For mild and moderate psoriasis:

  • Bathe daily to help remove scale and moisten the skin. Avoid harsh soaps; soap-substitutes are milder for your skin.
  • Apply moisturizers to all scaly psoriasis patches after any water exposure or bathing. Heavier, oilier ones help to retain water in the skin better than lighter moisturizers.
  • Apply hydrocortisone cream (0.5 or 1%), available over the counter, to help reduce itch and redness.
  • Use coal tar products, available over the counter as a shampoo, oil, gel, or cream. This is an old form of therapy, which can help, but it has a mild odor.
  • Use products with salicylic acid (shampoos, cleansers, and ointments) to help with removal of heavy scale.
  • Follow a healthy diet and stay at the right weight. (Being overweight may make psoriasis worse.)
Small doses of natural sunlight may be helpful, such as 10–15 minutes 2 or 3 times a week. Avoid too much sun, however, and protect your healthy skin from sun exposure.

These measures may also be helpful for people with severe psoriasis, who generally require medical care as well.

When to Seek Medical Care

See your doctor if you have severe psoriasis or if self-care measures are not helpful. Also, see your doctor if your psoriasis worsened or appeared after a sore throat; psoriasis can be triggered by a strep infection.

Treatments Your Physician May Prescribe

Unfortunately, there is no cure for psoriasis, but multiple treatments are very helpful at controlling it.

For disease that affects only the skin (localized disease), topical treatments may be prescribed:

  • Mid-to-high-potency topical steroids for the body or scalp and low-strength topical steroids for the face and skin fold areas as needed. Stretch marks and thinning of the skin can result from overuse of topical steroids, particularly in skin fold areas.
  • Vitamin D creams may be prescribed and are sometimes combined with topical steroids.
  • Vitamin A-based creams may be prescribed, sometimes in combination with topical steroids.
  • Calcineurin inhibitors (tacrolimus, pimecrolimus) may be prescribed.
  • Tar-based therapies are sometimes used. These therapies may have a foul odor and cause irritation in some people.
  • Anthralin creams may be prescribed, but these may stain skin and cause irritation.
  • For the scalp, oils, gels, foams, or solutions, some of which include topical steroids, are used in combination with tar or salicylic acid shampoos.
For more extensive disease:
  • If plaques are extensive, ultraviolet light therapy (phototherapy) may be considered.
  • Oral medications may be used for extensive psoriasis, including acitretin (made from Vitamin A), methotrexate, mycophenolate mofetil, cyclosporin A, and tacrolimus. These medications require close monitoring and may have potentially serious side effects.
  • Newer medications that affect the immune system may be injected at home, and other injected (intravenous) medications given in a medical facility are also available. These medications include etanercept, infliximab, adalimumab, alefacept, and felvizumab. These are very costly and may have serious side effects.

Trusted Links

National Psoriasis FoundationClinical Information and Differential Diagnosis of Psoriasis

References

Bolognia, Jean L., ed. Dermatology, pp.125-146. New York: Mosby, 2003.

Freedberg, Irwin M., ed. Fitzpatrick's Dermatology in General Medicine. 6th ed. pp.407, 1393-1394. New York: McGraw-Hill, 2003.