What’s the Difference Between Psoriatic Arthritis and Rheumatoid Arthritis?

Psoriatic arthritis (PsA) and rheumatoid arthritis (RA) are both types of inflammatory arthritis. But they aren’t exactly the same. You might think of them like hurricanes and tornadoes. They have a lot in common, but they’re definitely different.

Many different immunosuppressants can treat both PsA and RA. But some treatments only work for one condition or the other, so it’s important to determine exactly which condition you’re dealing with. 

Here, we’ll discuss differences between these two conditions, including causes, symptoms, and treatment options.

How are psoriatic arthritis and rheumatoid arthritis different?

The distinction between PsA and RA can be tricky sometimes. But certain signs and symptoms help rheumatologists — doctors who specialize in inflammation and arthritis — tell them apart. Here are a few examples. 

PsA vs. RA symptoms

Symptoms specific to PsA include:

• Pain and swelling of the joints nearest to the tips of the fingers and toes (RA doesn’t affect these)

• Symptoms unequal between sides of the body (asymmetrical)

• Psoriasis skin and nail changes

• Dactylitis, or swelling of an entire finger or toe like a sausage

• Tendon inflammation (enthesitis and tendonitis)

• Back pain and stiffness (spondylitis and sacroiliitis)

Symptoms specific to RA include:

• Symmetrical joint involvement (symptoms equal on both sides)

• Lung involvement (inflammation in the lungs, leading to scarring or lung nodules)

• Rheumatoid vasculitis (inflammation in the blood vessels leading to decreased blood flow to the skin, nerves, and eyes)

• Neck pain at the base of the head (inflammation at the top of the neck between the C1 and C2 vertebrae, sparing the rest of the spine)

• Positive blood tests, like rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP)

About 80% of people with RA test positive for RF or anti-CCP. Though rare, these people can also be positive in PsA. Researchers are trying to discover blood tests that could help tell the difference between PsA and RA. But these tests aren’t routinely available yet.

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PsA vs RA treatment

Treatments for PsA and treatments for RA are similar. Both involve immunosuppressants, which turn off pieces of the immune system that are too active. But there are some differences.

Initial treatment

According to 2021 RA guidelines, the first-choice treatment for RA is methotrexate. If methotrexate isn’t enough to control inflammation, then your healthcare team can add a biologic medication, like a TNF-alpha inhibitor. 

Generally speaking, the same holds true for PsA. But the 2018 PsA guidelines mention that going straight to a biologic instead of trying methotrexate first might be a better choice for some.

Ongoing treatment

After methotrexate and TNF-inhibitors, treatment options for PsA and RA can go down different paths. That’s because different parts of the immune system are overactive in each condition. 

For example, a biologic like Cosentyx (secukinumab) might work great for PsA. But it won’t be helpful for RA. On the other hand, a biologic like Actemra (tocilizumab) might work great for RA. But it’s no good for PsA. 

If all of this sounds confusing, that’s because it is. Try not to worry though. Your rheumatologist specializes in these medications. And they’ll work with you to find the treatment that’s best for your specific case.

What do psoriatic arthritis and rheumatoid arthritis have in common?

PsA and RA are both lifelong autoimmune conditions that cause inflammatory arthritis. The immune system is the body’s army. It normally protects against things that don’t belong (like infections). In PsA and RA, the immune system gets confused and starts attacking the body, not just things that shouldn’t be there. 

Causes

The causes of PsA and RA are “multifactorial.” That’s a fancy way of saying that there isn’t one single cause. The cause of these conditions is a combination of things that create the perfect storm: 

• Your genes

• A trigger from the environment (like toxin exposure)

• Infection

• Possibly something else 

Experts aren’t 100% sure what causes these conditions yet. But more research is being done regularly to find out.

Symptoms

Both RA and PsA can lead to the following symptoms:

• Joint pain and swelling: The most common sites are the hands and feet.

• Eye inflammation: PsA may cause uveitis or blepharitis. RA may cause episcleritis and scleritis.

• Heart disease: Due to uncontrolled inflammation, RA and PsA cause an increased risk of heart disease.

With both conditions, symptoms can go up and down. So some days may feel better than others. Flares — temporary worsening of symptoms — can happen in both PsA and RA.

Treatment

As mentioned above, many treatments for PsA and RA overlap. But sometimes the approach is different. A rheumatologist is the best person to help with this. That’s because they specialize in autoimmune and inflammatory conditions like PsA and RA. They’ll be a valuable member of your care team. 

The good news is that with advances in treatments, it’s possible to not only live with PsA and RA but to thrive.

Is psoriatic arthritis or rheumatoid arthritis worse?

There’s not a good answer for this. That’s because PsA and RA affect all people differently. So symptoms, flares, complications, and treatments are different for everybody, even within the same diagnosis. 

It’s important to know that both PsA and RA can cause complications if left untreated. But there are many treatment options for both that protect your body from long-term damage. 

Can you have both conditions at the same time?

Yes, it’s possible, but rare. Your rheumatologist can help you sort through your symptoms. With inflammatory conditions like these, though, recognizing your symptoms and starting treatment as soon as possible are what’s most important.

Why trust our experts?

Written by:

Samantha C. Shapiro, MD

Samantha Shapiro, MD, is a board-certified rheumatologist and internist with expertise in autoimmune and inflammatory conditions. She founded the division of rheumatology at Dell Medical School at The University of Texas at Austin.

Edited by:

Karla Robinson, MD

Karla Robinson, MD, is a medical editor for GoodRx. She is a licensed, board-certified family physician with almost 20 years of experience in health through varied clinical, administrative, and educational roles.

Reviewed by:

Mandy Armitage, MD

Mandy Armitage, MD, has combined her interests in clinical medicine with her passion for education and content development for many years. She served as medical director for the health technology companies HealthLoop (now Get Well) and Doximity.

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