Show Medically reviewed by Nancy Carteron, M.D., FACR — Written by Jon Johnson on July 22, 2021 Psoriatic arthritis and rheumatoid arthritis are easy to confuse. Both are forms of arthritis in which the immune system attacks the joints, causing pain, swelling, and stiffness. They are, however, distinct conditions. Arthritis is a common cause of chronic joint pain and stiffness in many people. There are multiple types of arthritis, each having its own causes, complications, and symptoms. Learn more about common types of arthritis here. Knowing the differences between psoriatic arthritis (PsA) and rheumatoid arthritis (RA) may help people understand the treatment options and what they might expect from them. In this article, we detail the differences between PsA and RA, including their symptoms, risk factors, diagnoses, and treatments.
Some key differences between PsA and RA are listed below. PsA characteristicsAround 30% of people with psoriasis have PsA. When a person has PsA, their immune system causes excess inflammation in their body. This inflammation often causes symptoms such as stiffness, swelling, and pain in the joints. Both sexes are affected by PsA. It occurs most commonly when people are between 30 and 50 years old. People with psoriasis will often develop shiny, discolored patches called plaques on their skin. These plaques form due to a buildup of excess skin cells. Learn more about psoriasis here. RA characteristicsRA affects around 1.3 million adults in the United States and up to 1% of the global population. When a person has RA, their immune system mistakenly attacks the tissues lining the joints, which can cause swelling, stiffness, and joint pain. RA will typically occur in more than one part of the body, and the symptoms often mirror each other. For example, a person may experience arthritis symptoms in both thumbs at once. The condition can be disabling if it is severe or left untreated. Anyone can get RA, but it may be most common in women and older adults. Both conditions cause joint stiffness, pain, and swelling. In both, symptoms may flare up and get worse and then go away temporarily. This pattern then repeats. Each condition also has additional symptoms. PsA symptomsSymptoms of PsA can include: RA symptomsSymptoms of RA can include:
PsA and RA both result from the immune system attacking healthy cells. Doctors still do not entirely understand what causes these diseases, but genetics, hormonal imbalances, and infections may play a part. About 30% of people with psoriasis develop PsA, and around 85% of PsA cases start before age 40. Close family history of psoriasis or PsA is a common risk factor in the disease. A 2018 study found that 31.9% of respondents with PsA had family members with the condition or other psoriasis types. A family history of RA may also increase a person’s risk of developing the condition. Other risk factors include obesity, smoking, and advancing age. Most people develop it in their sixties. Because people often confuse RA and PsA, getting an accurate diagnosis from a specialist called a rheumatologist is essential. The rheumatologist will likely ask about medical and family history. They will do a physical exam to look for specific signs of a condition. For example, a person who presents with scales or rough patches of skin is likely to have PsA, as these symptoms are not typical in RA. It is possible to have both RA and PsA, but this is rare. A rheumatologist may order blood tests or an X-ray to confirm a diagnosis. Rheumatoid factor testDoctors may also use a rheumatoid factor (RF) test to decide which of the two conditions a person has. People with RA have RF proteins in their bodies, while people with PsA do not typically have these proteins. People without RF proteins can also develop RA. This is known as seronegative RA and occurs in 20–30% of people with RA. Learn more about seronegative RA here. Imaging scansDoctors may use imaging tests such as X-rays, ultrasound, or MRI scans to see if there is any damage to bones, joints, or internal organs. In most cases, the treatment of the two conditions will be similar. Typically treatment aims to reduce or halt the inflammatory process that is common to both conditions. Treatment for both PsA and RA can include: Learn more about the difference between DMARDs and biologics here. There is no cure for either condition, but many people find they can manage pain and discomfort using the available treatment options under the guidance of a doctor or rheumatologist. Home remediesHome remedies and coping techniques may help a person manage PsA and RA symptoms. Regularly taking prescribed medication and avoiding known triggers can help people prevent flares. Arthritis can cause joint damage and stiffness. Regular exercise and courses of physical therapy may help a person maintain mobility and improve their quality of life. Eating a healthy diet and regular checkups with a rheumatologist can also be beneficial for anyone living with arthritis. If a person with PsA is also experiencing skin-related complications, topical ointments, such as corticosteroid creams, and anti-inflammatory medications may help. Learn more about home remedies for psoriasis here. PsA and RA have similar causes, symptoms, and treatments but are distinct conditions. Both primarily cause joint pain in the hands and feet and, if left unmanaged, can lead to severe complications. PsA typically affects the joints at the middle and end of a digit, occurs asymmetrically, and can spread to soft tissue. A person with PsA may also experience psoriatic skin conditions. By contrast, a person with RA will commonly experience symptoms in the knuckles and middle joints of their fingers in both hands and may present with rheumatoid nodules, among other complications. A rheumatologist will typically diagnose PsA or RA following a physical examination, a medical history assessment, blood tests, and scans. Treatment will focus on the long-term management of the condition and may include prescription medications, physical therapy, and in severe cases, surgery. If a person experiences symptoms of PsA or RA, they should consult a medical professional immediately. Read this article in Spanish. Last medically reviewed on July 22, 2021
Because psoriatic arthritis impacts the skin as well as the joints, it’s sometimes referred to as a “double whammy,” or “like rheumatoid arthritis but with a nasty skin rash,” according to the arthritis advocacy group Creaky Joints. Both psoriatic and rheumatoid arthritis are autoimmune disorders that cause joint inflammation, pain, and stiffness, as well as chronic fatigue. But there are differences in how the diseases develop and affect the joints. According to Kathleen Maksimowicz-Mckinnon, DO, a rheumatologist at Henry Ford Hospital in Detroit, there are some telltale signs that your arthritis pain is due to psoriatic arthritis, and not rheumatoid arthritis. These include:
RELATED: Signs and Symptoms of Psoriatic Arthritis Psoriatic Arthritis Versus OsteoarthritisJoint pain and stiffness, especially in the morning or after resting, can be a symptom of either psoriatic arthritis or osteoarthritis — the most common type of arthritis. Unlike autoimmune forms of arthritis, osteoarthritis is the result of wear-and-tear damage to cartilage — the slippery covering that allows bones to easily slide over each other when joints bend, says the Arthritis Foundation. Damage to the cartilage can result in bone grinding directly on bone, which causes pain and restricts movement. Osteoarthritis primarily affects the hands, knees, hips, and spine, and can create a grating sensation, along with popping or crackling, when you use the joint, says the Mayo Clinic. You may also notice hard lumps of bone near the joint or the joint may look distorted. While psoriatic arthritis symptoms tend to flare and subside, osteoarthritis-related pain and swelling usually become progressively worse over time. How Doctors Make a Psoriatic Arthritis DiagnosisDiagnosing psoriatic arthritis is typically a multi-step process. In addition to a physical exam and a comprehensive medical history, your doctor may order a number of tests. The different ways that psoriatic arthritis and rheumatoid arthritis impact the joints and tendons are often subtle and may not be detected in a physical exam but can be identified in imaging tests such as X-rays or ultrasound. Blood tests also help doctors differentiate psoriatic arthritis from rheumatoid arthritis. Although there is no blood test for psoriatic arthritis, doctors can look for the presence of two antibodies — rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) — that suggest a rheumatoid arthritis diagnosis, according to the Arthritis Foundation. RELATED: Psoriatic Arthritis Diagnosis Could Take More Than 2 Years, New Study Shows Treatment for Psoriatic Arthritis Differs From Other Forms of ArthritisThe main goals of all arthritis treatment are to reduce symptoms and improve quality of life. Methods vary depending on the type of arthritis. “Rheumatoid arthritis can be very destructive if it’s not treated, which is why we treat it aggressively with biologics,” says Ruderman. “But psoriatic arthritis doesn’t manifest that way. Fewer than half of people with psoriatic arthritis develop a particularly aggressive form, which makes treatment challenging because we don’t want to over-treat it.” Even so, the pain and discomfort associated with psoriatic arthritis can be significant. A study published in 2015 in the journal PLoS One found that the overall pain, joint pain, and fatigue reported by psoriatic arthritis patients was significantly greater than that reported by people with rheumatoid arthritis. Unless someone has an existing condition, such as elevated blood pressure or kidney disease, nonsteroidal anti-inflammatory drugs (NSAIDs) are recommended for joint symptoms in milder forms of psoriatic arthritis, says Husni. Topical creams, ointments, and lotions are often used to address the scaly, itchy skin rashes that occur with psoriasis. If there are signs of joint damage, doctors treat psoriatic arthritis more aggressively with medications like the ones used to treat rheumatoid arthritis, says Ruderman. These include disease-modifying anti-rheumatic drugs (DMARDs) and biologics. “Without disease-modifying therapy, the prognosis for psoriatic arthritis and rheumatoid arthritis is usually significantly worse than for osteoarthritis,” says Neil Kramer, MD, medical director of the Institute for Rheumatic and Autoimmune Diseases at Overlook Medical Center in Summit, New Jersey. As with rheumatoid arthritis, psoriatic arthritis complications can include increased risk of heart disease, depression, obesity, certain cancers (such as non-Hodgkin lymphoma), infections, and osteoporosis. In addition, “People with psoriasis or psoriatic arthritis have a high incidence of metabolic syndrome, fatty liver disease, and cholesterol abnormalities,” says Ruderman. “We need to think of it as psoriatic disease that affects the joints, tendons, skin, and nails, and use multiple things to treat it,” he adds. Additional reporting by Becky Upham. |