There isn’t one single test that diagnoses psoriatic arthritis (PsA). Still, your doctor can perform a variety of tests to determine your condition and also rule out other joint-related, inflammatory conditions.

Your doctor will first ask about your medical history and perform a physical exam. During your physical exam, they will look for swollen joints, patterns of pain or tenderness, and pitting or rash on your skin and nails.

Other diagnostic tests may include imaging tests, lab tests, and other evaluations. Your doctor may conduct tests to rule out conditions with symptoms similar to PsA, such as rheumatoid arthritis and gout.

This article explores which tests are used to diagnose psoriatic arthritis.

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Imaging tests allow your doctor to examine your joints and bones closely. Imaging tests used to diagnose PsA include:

Your doctor may notice changes to your body specific to PsA through an X-ray. An MRI can allow your doctor to look at other body parts, such as tendons and tissues, that are showing signs of PsA.

Your doctor will give you specific instructions before your imaging tests. This information will help you prepare for your appointment. You will undergo these tests at your doctor’s office or another medical facility.

Laboratory tests are also useful for diagnosing PsA. Your doctor can look for PsA characteristics from these tests to help determine your condition. Generally, lab tests will be conducted at your doctor’s office or another medical facility. These tests include:

  • Skin test: Your doctor may take a skin biopsy to diagnose psoriasis.
  • Fluid test: Your doctor can take fluid from a joint with suspected PsA to determine your condition.
  • Blood test: Most blood tests will not diagnose PsA but may point to a different condition. Inflammatory markers such as ESR and CRP are helpful but not diagnostic. Your doctor may look for certain factors in the blood, such as the rheumatoid factor. This factor indicates rheumatoid arthritis. If it’s present in your blood, you do not have PsA.

Your doctor may also look for signs of inflammation in your blood. However, people with PsA often have typical levels. Your doctor may also look for a PsA-related genetic marker but may find that it doesn’t necessarily diagnose the condition.

Researchers have concluded that three screening tools can help doctors determine whether you may have PsA. These include the Psoriasis and Arthritis Screening Questionnaire (PASQ), Psoriasis Epidemiology Screening Tool (PEST), and Toronto Arthritis Screen (ToPAS).

These screenings require you to complete a questionnaire. Your doctor will determine if you need further care based on your answers.

Your doctor may refer you to a rheumatologist if they cannot make a diagnosis. A rheumatologist is a doctor who specializes in musculoskeletal conditions such as psoriatic arthritis.

Aches and joint pains may indicate psoriatic arthritis (PsA). This is a chronic inflammatory condition that benefits from early diagnosis and treatment. You should see your doctor if you have symptoms of PsA. There are no specific tests to confirm PsA, but your doctor can use several diagnostic methods to determine your condition.

Symptoms of PsA include:

  • pain and inflammation in the joints
  • tiredness
  • swollen fingers and toes
  • stiffness and tiredness, particularly in the morning
  • mood swings
  • changes to the nails
  • eye irritation, such as redness or pain
  • limited motion in the joints

PsA may be experienced in the:

  • hands
  • wrists
  • elbows
  • neck
  • lower back
  • knees
  • ankles
  • feet
  • places where tendons meet joints, like the spine, pelvis, ribs, Achilles’ heel, and bottom of the foot

You may experience PsA after you develop psoriasis. The National Psoriasis Foundation reports research indicates that about 30% of people with psoriasis go on to develop PsA.

Remember that while the two conditions are linked, your experience with each can differ. For example, you may have limited psoriasis symptoms but severe PsA.

Psoriasis and PsA are both autoimmune conditions. It isn’t known what specifically leads to psoriasis or PsA. One factor could be genetics. Many people with these conditions have a family member with the same condition.

Other risk factors include certain age and infections that trigger the immune system. Most people typically start experiencing symptoms and are diagnosed with the condition in their 30s, but the typical diagnostic window extends to age 50 years.

You may be diagnosed with PsA after testing. Then your doctor will determine a treatment plan for your level of PsA based on your test results, symptoms, and overall health.

Your treatment plan may include one or more of the following:

You may also consider the following lifestyle changes to help ease symptoms of PsA:

Easing PsA symptoms

  • Practice healthful eating habits, such as following a Mediterranean or gluten-free diet.
  • Stay physically active, such as exercising regularly, to help maintain a moderate weight. because Additional weight is an inflammatory trigger for the body and can put unnecessary pressure on your joints.
  • Get adequate rest.
  • Avoid strenuous activities, such as high impact sports, that can pressure your joints.

Here are some frequently asked questions about tests for psoriatic arthritis.

How do they test for psoriatic arthritis?

Doctors use X-rays, MRIs, CT scans, and ultrasounds to examine your bones and joints closely.

What are the first symptoms of psoriatic arthritis?

Experiencing aches and pains in your joints is most likely the first symptom. It’s important to schedule a visit with your doctor or another healthcare professional to undergo proper testing.

What can be mistaken for psoriatic arthritis?

Rheumatoid arthritis (RA) or osteoarthritis (OA) can often be mistaken for PsA.

PsA is chronic and will not go away on its own, so you need to get treatment for it. The longer you wait to receive a proper PsA diagnosis and start treatment, the more damage your joints may incur. Scheduling regular appointments with your doctor to discuss your PsA is important. They can prescribe treatment to help alleviate symptoms and prevent the condition from getting worse.

To help improve your condition, your doctor may recommend reducing calorie intake, increasing physical activity, and eating more fruits, vegetables, and healthy fats.

Additionally, PsA is linked to other conditions that are influenced by inflammation, such as obesity and diabetes. Properly treating PsA can lower your risk of these related conditions.

Be sure to contact your doctor if your existing symptoms worsen or if you develop new symptoms.