Psoriatic and rheumatoid arthritis are inflammatory conditions with many similar symptoms. However, both conditions can have different causes, outlooks, and treatments.

Arthritis is inflammation of the joints and, sometimes, their surrounding and connective tissues.

There are nearly 100 arthritic conditions, but psoriatic arthritis (PsA) and rheumatoid arthritis (RA) are two of the most common.

PsA and RA share many similarities, such as:

  • symptoms like pain, stiffness, and swelling
  • they’re both autoimmune diseases
  • they both gradually damage a person’s joints, bones, and tendons

That said, these two arthritic conditions may have different causes, manifestations, and treatments.

Rheumatoid arthritis (RA)

RA is the most common type of chronic autoimmune arthritis.

This means your immune system mistakenly attacks the healthy cells and tissues in your joints, causing pain and inflammation.

This condition affects over 1.3 million people in the United States. Females are 2–3 times more likely to develop RA, and the onset of symptoms typically occurs between ages 30 and 50.

If left untreated, RA can gradually cause joint damage and affect some organs like the heart, kidneys, and lungs.

Psoriatic arthritis (PsA)

PsA is also a chronic inflammatory autoimmune disease that may cause a combination of pain, stiffness, and swelling in your joints.

However, it is typically related to psoriasis, a condition that causes your immune system to produce skin cells too quickly. This may lead to painful red bumps and silver scales forming on the skin’s surface.

Research reports that in 2020, 7.5 million U.S. adults ages 20 and older were affected by psoriasis.

Up to 30% of people with psoriasis could develop PsA in their lifetime.

Unlike RA, PsA affects both males and females equally. The condition usually appears between ages 30 and 50, and may develop 5–10 years after psoriasis starts.

That said, some people may develop PsA before having noticeable psoriasis skin symptoms.

The causes for PsA and RA aren’t so clear.

It’s estimated that 1 in 3 people with psoriasis may develop PsA, with males and females being affected equally.

On the other hand, females are 2–3 times more likely to develop RA, which is not associated with a skin disease.

All the causes of RA are still not known. However, it’s believed that genetics, epigenetics, and environmental factors play a role in developing the condition.

Certain risk factors may increase a person’s chances of developing arthritis, such as:

Both RA and PsA are inflammatory conditions that may cause pain, stiffness, and swelling in your joints.

Symptoms typically begin in the small joints of your hands and feet or your knees.

They could develop over several weeks and may eventually cause bone and tissue damage, unsteadiness, and deformity.

The severity of your symptoms may also fluctuate. They may ease for a period of time (remission) or get worse (flares).

Despite these similarities, both conditions may manifest differently and be accompanied by varying symptoms.

Rheumatoid arthritis

RA joint inflammation typically has a symmetrical distribution. This means it affects the same joint on both sides of the body, though this may not always be the case.

RA may also have a larger number of joints involved compared with PsA.

Symptoms of RA may include:

  • throbbing and aching pain
  • stiffness in the morning that typically lasts longer than 30 minutes
  • hot, tender, and swollen joints
  • rheumatoid nodules, which are lumps that may appear under your skin
  • loss of energy, appetite, and weight
  • fever
  • vasculitis rash, though this complication is less frequent with advanced treatments

Psoriatic arthritis

Unlike RA, PsA symptoms aren’t typically symmetrical. For example, your left hand or foot may be affected, but not the right limbs.

PsA may involve entheses inflammation, which are the areas where your tendons, ligaments, and joint capsules attach to your bones. It may also cause sacroiliac (SI) joint inflammation in the spine (sacroiliitis). These are not features of RA.

Having a combination of the following six symptoms may also be a sign of PsA:

The severity of PsA symptoms doesn’t always correlate with the severity of psoriasis. You may have mild symptoms of PsA and severe skin lesions, or vice-versa.

Speak with a doctor if you’re experiencing joint pain, stiffness, or other symptoms of arthritis.

To diagnose RA or PsA, they may perform:

It could be difficult for a doctor or rheumatologist to determine PsA or RA in their early stages because both conditions may mimic the other.

RA and PsA are both chronic conditions. Although there’s currently no cure for either, prevention and treatment aim to help:

  • reduce the severity of symptoms
  • minimize joint, bone, and tendon damage
  • improve or maintain quality of life and physical function

For both conditions, a treatment plan may include some of the following types of medications:

Your treatment plan may also include physiotherapy to help maintain or improve your mobility.

How can you tell the difference between rheumatoid arthritis and psoriatic arthritis?

Rheumatoid arthritis (RA) and psoriatic arthritis (PsA) may be difficult to differentiate in their early stages because of their similar symptoms.

That said, symptoms associated with RA may include:

  • throbbing, aching, and symmetrical joint pain
  • morning joint stiffness that may last 30 minutes or more
  • rheumatoid nodules
  • loss of energy, appetite, and weight

What are the six signs of psoriatic arthritis?

Psoriatic arthritis (PsA) may be caused by psoriasis, which is a chronic autoimmune disease involving the skin.

Pain, stiffness, and inflammation are typically asymmetrical. This means they may be present on one side of your body but not the other.

Six other common symptoms of PsA include:

  • morning joint stiffness
  • nail flaking or pitting
  • eye pain or redness
  • fingers that are swollen like sausages
  • back pain
  • pain where the ligaments and tendons join bones

It’s important to speak with a doctor if you think you may have PsA or RA.

If either of these conditions is left untreated, significant damage may be done to your joints, bones, and tendons over time. This might lead to possible surgeries or disabilities.

But with the help of a doctor and other medical professionals, PsA and RA symptoms may be treated to maintain or improve your quality of life.