Find information on medical topics, symptoms, drugs, procedures, news and more, written in everyday language.

* This is the Consumer Version. *

Psoriatic Arthritis

by Roy D. Altman, MD

Psoriatic arthritis is a spondyloarthritis and a form of joint inflammation that occurs in some people who have psoriasis of the skin or nails.

  • Joint inflammation can develop in people who have psoriasis.

  • Joints commonly involved include the hips, knees, and those closest to the tips of the fingers and toes.

  • The diagnosis is based on symptoms.

  • Nonsteroidal anti-inflammatory drugs, methotrexate, cyclosporine, and tumor necrosis factor inhibitors (such as adalimumab, etanercept, and infliximab) and sometimes phototherapy can help.

Psoriatic arthritis is a type of spondyloarthritis (see Spondyloarthritis).

Psoriatic arthritis resembles rheumatoid arthritis but does not produce the antibodies characteristic of rheumatoid arthritis. Psoriatic arthritis occurs in about 5 to 40% of people with psoriasis (a skin condition causing flare-ups of red, scaly rashes and thickened, pitted nails—see see Psoriasis). People with a certain gene ( HLA-B27 ) and those who have affected family members are at increased risk of psoriatic arthritis. The cause of psoriatic arthritis is unknown.


Inflammation often affects joints closest to the tips of the fingers and toes, although other joints, including the hips, knees, and spine, are often affected as well. Often, the joints of the upper extremities are affected more. Back pain may be present.

The joints may become swollen and deformed when inflammation is chronic. Psoriatic arthritis affects joints asymmetrically (more on one side of the body than the other), more so than rheumatoid arthritis, and involves fewer joints.

The psoriasis rash may appear before or after arthritis develops. Sometimes the rash is not noticed because it is hidden in the scalp, navel, or creases of the skin such as between the back of the buttocks and thigh. The skin and joint symptoms sometimes appear and disappear together.


  • Drugs

  • Phototherapy

Treatment of psoriatic arthritis is aimed at controlling the rash and relieving the joint inflammation. Several drugs that are effective in treating rheumatoid arthritis (see Rheumatoid Arthritis (RA) : Drugs for Rheumatoid Arthritis) are also used to treat psoriatic arthritis, particularly nonsteroidal anti-inflammatory drugs (NSAIDs), methotrexate, cyclosporine, and tumor necrosis factor (TNF) inhibitors (such as adalimumab, etanercept, infliximab, certolizumab pegol, and golimumab). TNF inhibitors are particularly effective for psoriatic arthritis.

Ustekinumab, given by injection, and apremilast, taken by mouth, can be used to treat moderate to severe psoriatic arthritis.

Some people take methoxsalen (psoralen) by mouth and undergo psoralen plus ultraviolet A light treatments (phototherapy). This combination relieves the skin symptoms and most of the joint inflammation but may not help inflammation of the spine.

Drugs Mentioned In This Article

  • Generic Name
    Select Brand Names