How is psoriatic arthritis diagnosed?

Like psoriasis, psoriatic arthritis is a chronic disease related to the immune system. Psoriatic arthritis affects the joints and entheses (the places where tendons and ligaments connect to bone). It can cause pain, fatigue, stiffness and swelling. Left untreated, psoriatic arthritis can result in permanent joint damage. This is why it’s important to get the correct diagnosis when symptoms appear and start treatment as soon as possible.

There are many ways to diagnose psoriatic arthritis. Your health care provider will diagnose you by examining your skin, nails, joints and other symptoms. You may have X-rays, an MRI, an ultrasound and blood tests as well.

Psoriatic arthritis may sometimes be incorrectly diagnosed as other types of arthritis or other conditions. However, psoriatic arthritis has characteristics and unique symptoms that may be present and can help your provider reach the correct diagnosis.

These symptoms include:

  • Presence of psoriasis
  • Swelling, tenderness and inflammation of the joints, often in an asymmetric pattern (not the same on the left and right sides of the body)
  • Morning stiffness or stiffness after resting
  • Nail changes such as the nail separating from nail bed, becoming pitted, changing color or resembling a fungal infection
  • Swelling of whole fingers or toes rather than just knuckles (also called dactylitis or “sausage digits”)
  • Asymmetric joint symptoms (not the same on the left and right sides of the body)
  • Enthesitis (pain and swelling of the entheses or places where tendons and ligaments connect to bone, pronounced en-thi-SAI-tis) that commonly affects areas such as the bottoms of the feet, heels, hips or the spine
  • Inflammatory-type back pain that is worse with rest and better with activity

A rheumatologist (a doctor who specializes in the diagnosis and treatment of arthritis and other diseases of the joints, muscles and bone) who has experience treating psoriatic arthritis may be best for diagnosing and managing your disease.

If you think you might have psoriatic arthritis, you can learn more by taking a short five-question quiz. (Our quiz is based on the Psoriasis Epidemiology Screening Tool. Your health care provider may use other types of tests to diagnose you.)

Get the facts about PsA

Get more information on treatment options and symptoms of psoriatic arthritis, along with a flare tracker to help monitor your disease and understand your unique triggers. Request your free PsA kit today.


Last updated  by the National Psoriasis Foundation.