What is psoriatic arthritis?
Psoriatic arthritis is a type of arthritis that develops in people who have psoriasis. Psoriasis is a condition that causes patches of red, dry skin. Up to 30 percent of people with psoriasis will develop psoriatic arthritis.
Psoriatic arthritis can happen suddenly or slowly over time. In about 80 to 90 percent of cases it develops after psoriasis is diagnosed. Most people with psoriatic arthritis first see symptoms develop between the ages of 30 and 50.
Symptoms include fatigue, joint swelling and tenderness, and reduced range of motion. Sometimes fingernails appear to be infected and have a scaly appearance. Fingertips and toes tend to swell. Your joints may also feel warm to the touch.
Psoriatic arthritis most often affects the following body parts:
- wrists
- spine
- fingers
- eyes
- neck
If you are experiencing joint stiffness, pain, or swelling that persists, you should see a doctor.
Types of psoriatic arthritis
There are different kinds of psoriatic arthritis. According to the Arthritis Foundation, about 50 percent of people diagnosed with psoriatic arthritis have a type called symmetric psoriatic arthritis. It occurs in joints on both sides of the body at the same time and can be disabling.
Asymmetric psoriatic arthritis is the second most common form. It affects 35 percent of people with psoriatic arthritis. It's considered the mildest form because it usually doesn't affect more than three joints.
The other types of psoriatic arthritis are not as common. Each has specific, serious symptoms:
- Arthritis mutilans deforms small joints in the fingers and toes.
- Spondylitis affects the neck and shoulder joints.
- Distal interphalangeal predominant affects the joints in the ends of the fingers.
Skin disease
According to the National Psoriasis Foundation, psoriasis occurs before psoriatic arthritis in 85 percent of people diagnosed. If you have psoriasis and develop joint aches, pains, or swelling, consult with your doctor. The mildness or severity of your psoriasis does not necessarily relate to the severity of the arthritis.
Psoriatic arthritis can also occur when psoriasis doesn't appear on the skin. This means that you can still have psoriatic arthritis even if you don't have a psoriasis diagnosis.
And psoriatic arthritis can develop after a joint injury and lead to bursitis or tendonitis. Bursitis occurs when the small, fluid-filled sacs that cushion your joints become inflamed and painful.
Why you need a rheumatologist
There's no single test for psoriatic arthritis. It may take time to reach a diagnosis and your doctor or dermatologist may refer you to a rheumatologist.
A rheumatologist is a doctor who specializes in diagnosing and treating arthritis. Be prepared to list all your symptoms, give a complete medical history, and tell you doctor if you've been diagnosed with psoriasis.
Your rheumatologist will conduct a physical exam, and may ask you to perform simple tasks that demonstrate your range of motion.
Diagnosing psoriatic arthritis can be like solving a mystery. Your rheumatologist may perform tests to rule out other forms of arthritis, including gout, rheumatoid arthritis (RA), and reactive arthritis.
They may look for an elevated sedimentation rate, which indicates some amount of inflammation. And your rheumatologist may also order X-rays, MRI scans, ultrasounds, or CT scans to look for joint damage.
Repeated flare-ups
People with arthritis can experience periods of increased disease activity called flare-ups. Symptoms of a flare-up include muscle and joint pain and swelling. You may also have tendonitis and bursitis.
In psoriatic arthritis, fingers and toes may swell up. This is called dactylitis. You may also experience pain and swelling in your wrists, knees, ankles, or lower back.
Repeated flare-ups can help your doctor make a psoriatic arthritis diagnosis. At times, a psoriasis flare-up will coincide with a psoriatic arthritis flare-up. The same things can trigger flare-ups of both conditions.
Blood tests
Psoriatic arthritis cannot be diagnosed with a simple blood test. However, symptoms of psoriatic arthritis are similar to those of RA, so your doctor will probably order a blood test to rule out RA.
The test will determine if your blood is positive for rheumatoid factor (RF). This is an antibody found in the blood of people with RA. You doctor may also order a blood test to look for an elevated C-reactive protein.
Blood tests can also help rule out gout and osteoarthritis. If you have psoriatic arthritis, tests may show high levels of inflammation or mild anemia.
None of these signs and symptoms alone can confirm psoriatic arthritis. Your doctor must examine all the evidence to confirm the diagnosis.
Imaging tests
X-rays are not always useful in diagnosing early stage psoriatic arthritis. As the disease progresses, your doctor may use imaging tests to see changes in the joints that are characteristic of this type of arthritis.
MRIs alone can't diagnose psoriatic arthritis, but they may help detect problems with your tendons and ligaments. CT scans and ultrasounds can help determine progression.
Joint fluid tests
People with psoriatic arthritis can be misdiagnosed with gout, a form of arthritis caused by too much uric acid in the body. Gout usually affects the big toes.
Your doctor can take fluid from an affected joint to determine if it contains uric acid crystals. Your doctor can also rule out, or diagnose, gout through this test.
It's also possible to have gout, psoriasis, and psoriatic arthritis at the same time.
Treatment
Once you've been diagnosed, your treatment plan will depend on the severity of your symptoms. For joints that are painful, but not yet at risk of being damaged, over-the-counter anti-inflammatory drugs may be recommended. These include ibuprofen (Motrin or Advil) and naproxen (Aleve). More severe pain might require a prescription anti-inflammatory painkiller.
Disease-modifying anti-rheumatic drugs can save a joint from being damaged by psoriatic arthritis. Examples include methotrexate (Trexall) and sulfasalazine (Azulfidine). These drugs might help to slow disease progression if you are diagnosed in the early stages of psoriatic arthritis.
Some treatments can improve symptoms of both psoriasis and psoriatic arthritis. But the success of these treatments varies from person to person.
If you are diagnosed after you have had psoriatic arthritis for some time, your treatment decisions will be affected. Your doctor may prescribe an immunosuppressant to prevent flare-ups and keep your joints from being damaged further.
Biologics such as TNF-alpha inhibitors are another treatment that reduces pain. However, there can be serious safety concerns such as increased risk of infection.
Finally, if joint damage must be addressed more directly, your doctor might want to start with a steroid injection at the site of the affected joint. There are also situations where psoriatic arthritis results in joint replacement surgery.
Takeaway
Traditional medicine is not the only treatment option for psoriatic arthritis. There are lifestyle choices that could make your condition more comfortable. These include changes in diet and adopting an exercise regimen. Maintaining a healthy weight, limiting starch, and taking steps to protect your joints will also help.
Identify your flare-up triggers and avoid them. Also, your family history may be predictive of whether or not you have psoriatic arthritis, so keep that in mind.
Psoriatic arthritis, when treated, can usually be slowed down to prevent further joint damage.
Read more in Moderate to Severe Psoriatic Arthritis Pain Resources
