What is the difference between rheumatoid arthritis and osteoarthritis and psoriatic arthritis

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 characteristics

Around 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 characteristics

RA 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 symptoms

Symptoms of PsA can include:

• swelling and pain in at least one joint
• back pain or sacroiliac pain, which may be severe
• swelling in the fingers and toes
• inflammation of the eyes
• foot pain, typically in the heel or sole

RA symptoms

Symptoms of RA can include:

• joint pain, often in the fingers or hands
• fever
• dry mouth
• dry eyes
• general fatigue
• inflammation of the eyes
• loss of appetite
• increased stiffness in joints in the morning

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 test

Doctors 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 scans

Doctors 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:

• nonsteroidal anti-inflammatory drugs
• corticosteroids
• physical therapy
• immunosuppressants
• surgery to repair, replace, or stabilize damaged joints
• disease-modifying antirheumatic drugs (DMARDs)
• biologics, which target specific components of the immune system

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 remedies

Home 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.