Rheumatoid Arthritis vs. Psoriatic Arthritis: What’s the Difference?

Causes and Risk Factors of Psoriatic Arthritis and Rheumatoid Arthritis

Psoriatic and rheumatoid arthritis are both conditions that affect the joints of the body with episodes of painful inflammation. With each, an overactive immune system attacks the body, causing inflammation that can damage skin, joints, and tendons. If left untreated, these conditions can each get progressively worse.

The specific causes of these forms of arthritis are unknown, says Alireza Meysami, M.D., head of the Division of Rheumatology at the Henry Ford Health System in Detroit, Michigan, and an associate professor of medicine at Wayne State University. “Both psoriatic arthritis and rheumatoid arthritis, however, do have a genetic component and tend to run in families.”

For example, people are at higher risk for psoriatic arthritis if they have psoriasis or if a family member does. In fact, having psoriasis is the single greatest risk factor for developing psoriatic arthritis, Meysami says.

Some lifestyle factors may increase the risk of developing both psoriatic and rheumatoid arthritis, Meysami says, including smoking, gingivitis, and poor dental health. Surprisingly, periodontitis—an inflammatory oral disease—is very common among people with rheumatoid arthritis, according to the journal Arthritis Research & Therapy. People who are obese are at higher risk for psoriatic arthritis, according to research.

Women are three times more likely to get rheumatoid arthritis, according to research published in the Bulletin on the Rheumatic Diseases, while psoriatic arthritis tends to affect men and women in equal numbers. One theory is that genes specific to the X chromosome may be linked to rheumatoid arthritis, causing a larger number of women to be affected, according to a study published in Nature Genetics. Another theory is that sex hormones may affect development of the disease.

Both types of arthritis can occur at any age. Psoriatic arthritis most commonly appears when someone is in their 30s to 50s, says Meysami. The onset of rheumatoid arthritis is most common after age 60, according to the Centers for Disease Control and Prevention.

Do Psoriatic Arthritis and Rheumatoid Arthritis Have Different Symptoms?

Whether you have psoriatic or rheumatoid arthritis, you may experience joint pain, tenderness, and stiffness, particularly in the hands and feet, and often first thing in the morning. Fatigue is very common, too. Both conditions have ups and downs, with periods when patients feel much better, as well as flare-ups when symptoms act up. Symptoms can also lead to depression due to the physical and emotional effects of these diseases, says Meysami.

Up to 80 percent of the time, people with psoriatic arthritis also have skin and/or nail symptoms, according to an article published in the journal Reumatologia. You may see thick, red, dry, itchy patches of skin with silvery scales, called plaques, anywhere on the body, including on the scalp. Nails may begin peeling and separating from the nail bed. Nail and skin symptoms do not typically occur with rheumatoid arthritis, Meysami says.

Another common symptom of psoriatic arthritis is called dactylitis, where toes and fingers swell like sausages and redden. All joints may be affected, but it is most common in the knees, ankles, lower back, and spine.

Psoriatic arthritis is often asymmetrical, so someone might be affected on just one side of their body, or in different locations, like on the right hand and left leg.

“Rheumatoid arthritis usually impacts the small joints in the hands and feet, the hips, shoulders, elbows, and knees, but rarely the spine,” says Max Hamburger, M.D., chief medical officer of United Rheumatology in Long Island, New York, and founding president of the New York Rheumatology Society. “It is a more symmetrical condition, characterized by mirroring. This is when identical joints are affected in pairs on both sides of the body, with both wrists, hands, and feet inflamed.”

With rheumatoid arthritis, people might develop rheumatoid nodules, which are lumpy lesions around pressure sites like the elbows and ankles, according to the Johns Hopkins Arthritis Center. These usually develop later in the disease course or with long-standing disease.

In general, people with psoriasis should pay attention to any physical changes beyond their skin symptoms, including increased joint stiffness, neck and back pain, and fatigue and discuss them with their doctor.

A board-certified rheumatologist can determine which type of arthritis you may have. The doctor will ask about your symptoms and may order blood tests to help distinguish between the two conditions. X-rays may also be performed to see the joint involvement visually.

Can You Have Both Psoriatic Arthritis and Rheumatoid Arthritis?

Yes, a person can have both of these conditions at the same time, Meysami says, or a doctor may not be able to distinguish between two, since the symptoms can be so similar. Initial treatment for both of these forms of arthritis can be similar, so if it’s unclear which one you have, your doctor may take a trial-and-error approach to find out what medication is effective for you.

What Are the Treatments for Psoriatic Arthritis and Rheumatoid Arthritis?

Both are chronic, progressive diseases with no cure, but there are effective treatments to control them, says Hamburger.

Medication can help manage pain and provide significant relief from symptoms of both types of psoriasis. Common treatments include anti-inflammatory medications and immune-system modulators, such as methotrexate. For both rheumatoid and psoriatic arthritis, a subset of disease-modifying antirheumatic drugs (DMARDS) called biologics may be prescribed to slow the condition’s progression.

If left untreated, both psoriatic and rheumatoid arthritis can cause permanent erosion of the joints. They can also put you at risk for eye and lung inflammation, and serious complications like cardiovascular disease, according to the Arthritis Foundation. It’s important to see a doctor right away if you see signs of either of these conditions, so you can get an accurate diagnosis and start treatment early to prevent joint damage.

What Else Should You Know About Inflammatory Arthritis?

Doctors may suggest an anti-inflammatory diet and regular exercise to help keep symptoms under control. It’s also a good idea to seek support if you’re feeling anxious or depressed, as it can be a vicious cycle: the pain and inflammation of arthritis is connected with anxiety and depression, and mental health issues can worsen arthritis symptoms, according to the Arthritis Foundation. With psoriatic arthritis, patients should see both a rheumatologist and a dermatologist who can work together as a team to treat both joint and skin symptoms. “Good collaboration is a must,” says Meysami.

The treatments available today, including medication and lifestyle modifications, can be very effective at helping people manage their symptoms and live comfortably with psoriatic or rheumatoid arthritis, says Meysami. “That’s great news for our patients.”

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