Both psoriatic arthritis and rheumatoid arthritis are inflammatory autoimmune conditions. Their symptoms are similar, including joint stiffness, pain, inflammation, and exhaustion.
Because each is a type of arthritis, many people aren’t sure about the differences and relationship between PsA and RA. As one MyPsoriasisTeam member asked, “Is there a link between psoriasis and rheumatoid arthritis?”
Ultimately, there are a few key similarities and differences between the causes, symptoms, and treatment of PsA and RA.
Psoriatic arthritis occurs when the immune system mistakenly attacks the body’s own healthy tissues instead of foreign invaders, like viruses and bacteria. Unlike rheumatoid arthritis, psoriatic arthritis is related to psoriasis. Psoriasis causes scaly, discolored patches on the skin, which can burn or itch.
Rheumatoid arthritis is one of the most common types of inflammatory arthritis, affecting more than 1.3 million people in the United States. Like PsA, it occurs when the immune system attacks healthy cells and tissues in the joints and in the ligaments and tendons attached to the joints. RA, in particular, targets the lining of the membranes surrounding the joints (called the synovium), causing joint inflammation and permanent joint damage.
Some of the causes of psoriatic and rheumatoid arthritis overlap, and others are specific to PsA.
Rheumatoid arthritis is caused by the immune system attacking the synovium, leading to inflammation. Over time, the thickened synovium can damage the cartilage and bone within the joint.
As is the case with psoriatic arthritis, the exact cause of RA is unknown. Scientists believe that environmental factors (such as smoking, pollution, or infections), in combination with genetic factors, cause RA. A family history of RA also makes you more likely to develop this condition.
Having psoriasis is the top risk factor for developing psoriatic arthritis. As with RA, both genetic and environmental factors, as well as family history and genes, are thought to contribute to the development of PsA.
Most people who develop psoriatic arthritis show the skin symptoms of psoriasis first, although some individuals have PsA but never have psoriasis symptoms. About 30 percent of people with psoriasis eventually develop PsA.
The severity of a person’s psoriasis symptoms is not linked to the severity of their PsA symptoms. Some people may have severe psoriasis lesions but mild PsA symptoms. Others may have mild lesions but severe PsA joint pain.
Joints affected by psoriatic or rheumatoid arthritis can feel painful, stiff, swollen, and hot. The symptoms of PsA and RA tend to show up in different joints. PsA tends to be asymmetric, meaning it affects different joints on either side of the body. RA is more likely to cause joint pain and stiffness in the same joints on both sides of the body, such as both hands or wrists.
The two diseases, for instance, affect different parts of the spine. Psoriatic arthritis sometimes leads to a condition called spondylitis that causes neck or back pain. Up to half of all people with PsA will experience spondylitis pain. Rheumatoid arthritis, on the other hand, often causes cervical spine problems in the neck. Up to 80 percent of people with RA experience neck pain.
RA is also more likely than PsA to affect the hands, such as the joints in the wrists and fingers. Additionally, both psoriatic and rheumatoid arthritis affect different small joints in the fingers and toes. RA affects the first two joints, and PsA attacks the joint closest to the nail bed.
People with PsA can experience dactylitis, a condition in which the fingers or toes swell up and resemble sausages. Dactylitis is often the first symptom of PsA, and it may be the only joint symptom a person experiences for several years.
In addition to joint swelling and nail changes, psoriatic and rheumatoid arthritis can cause skin conditions.
People with PsA are more likely to have psoriasis. The two conditions are so closely linked that they are often referred to collectively as psoriatic disease. Psoriasis causes an overproduction of skin cells, which can lead to raised, scaly rashes on the knees, elbows, trunk, scalp, and other areas of the body. These rashes may be skin symptoms of psoriatic arthritis. PsA also affects the nails. People with PsA and psoriasis often have pitted, ridged nails, which appear similar to nails with a fungal infection.
The most common skin change in people with RA is the appearance of nodules. These flesh-colored lumps can be seen or felt just beneath the skin. They may be tender but are not often painful. Nodules are common, affecting up to 25 percent of people with RA.
People with RA can also develop rashes and nail symptoms.
If you notice any rashes, lumps, or other changes to your skin or nails, talk to your doctor or rheumatologist.
Some MyPsoriasisTeam members have shared that diagnosing PsA and RA can be tricky. One member asked, “How can they know for certain if you have psoriatic arthritis or rheumatoid arthritis? I’ve had all kinds of blood tests done!”
Another member replied, “It’s difficult, but they know what to look for. PsA affects different joints in the fingers than rheumatoid arthritis. The best way to find out is to see a rheumatologist.”
Imaging tests, such as X-rays and MRI, are useful in diagnosing both psoriatic and rheumatoid arthritis, as well as learning how far the disease has advanced. PsA and RA can produce different patterns of inflammation on imaging scans.
Blood tests can also help tell the difference between PsA and RA.
About 80 percent of people with rheumatoid arthritis are said to have seropositive RA, which means they test positive for rheumatoid factor (RF) or cyclic citrullinated peptide (CCP) antibodies. However, it’s also possible to have seronegative RA, which means you’re diagnosed with RA even though your blood test results are negative for the condition.
Most people with psoriatic arthritis do not have RF or CCP antibodies and are considered to have seronegative inflammatory arthritis.
Many of the same medications options are used to treat both psoriatic and rheumatoid arthritis. Some drugs that are used to treat PsA are also approved for psoriasis. Your doctor can help you understand the best option for you.
Over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin and Ibuprofen, are useful for managing mild to moderate symptoms of psoriatic arthritis and rheumatoid arthritis. These drugs can help reduce inflammation and swelling.
Injecting corticosteroids into joints can provide quick relief for PsA and RA symptoms. But the side effects associated with steroid use — and with oral steroids in particular — mean these medications are not a good long-term option for treating joint pain. Steroids are often used short term to treat rheumatoid arthritis or psoriatic arthritis flares.
Disease-modifying antirheumatic drugs (DMARDs) have been proved in clinical studies (studies that investigate new drugs) to stop or slow the disease process in people with inflammatory arthritis. Methotrexate (sold as Otrexup, Rasuvo, and Trexall) is the most commonly used DMARD for RA. It may not be as effective in treating PsA, although studies show mixed results.
Biologic DMARDs are injected medications that target certain parts of the immune system that contribute to inflammation. They may be given for severe cases of PsA or when other drugs haven’t worked. The U.S. Food and Drug Administration (FDA) has approved several biologic DMARDs for treating both PsA or RA. These medications include:
Other biologic medications are available to treat either PsA or RA but not both.
A newer class of DMARDs called Janus kinase (JAK) inhibitors also provides symptom relief for people with PsA and RA. JAK inhibitors work by interfering with your body’s ability to create JAK enzymes, which can cause inflammation and other immune responses. The FDA has approved two JAK inhibitors for the treatment of PsA and RA: Xeljanz (a formulation of tofacitinib) and Rinvoq (a formulation of upadacitinib). There is a third JAK inhibitor available to treat RA.
You can have both PsA and RA. However, because you also could have just one of the conditions, you should talk to your doctor or rheumatologist if you are confused about your symptoms. Additionally, some people with PsA never experience the obvious skin disease symptoms of psoriasis, making it easy to confuse PsA with RA.
In people who have both psoriatic and rheumatoid arthritis, the symptoms may sometimes overlap or come and go. As one MyPsoriasisTeam member shared, “My psoriasis has cleared up a lot, but my rheumatoid arthritis and psoriatic arthritis have gotten worse.”
MyPsoriasisTeam is the social network for people with psoriatic arthritis and psoriasis and their loved ones. Here, more than 112,000 members come together to share their stories, ask and offer advice, and discuss life with PsA and RA.
Those diagnosed with rheumatoid arthritis might consider joining myRAteam, a support network for RA that is more than 198,000 members strong.
Have you been diagnosed with PsA and RA? Are you wondering if you may have RA in addition to PsA? Let us know in the comments below, or start a conversation on MyPsoriasisTeam.