Rheumatoid Arthritis vs. Psoriatic Arthritis

Reviewed on 3/28/2022
Psoriasis on the arms
Both rheumatoid arthritis (RA) and psoriatic arthritis cause joint pain and stiffness. RA usually affects the same joints on both sides of the body (symmetrical). Psoriatic arthritis commonly affects the knees and ankles.

Joint symptoms are the main symptom of most types of arthritis, including rheumatoid arthritis and psoriatic arthritis.

Joint symptoms of both rheumatoid arthritis and psoriatic arthritis include:

  • Pain
  • Stiffness
  • Swelling 
  • Tenderness
  • Redness
  • Warmth
  • Limited movement/decreased range of motion or flexibility

A difference in the joint pain of rheumatoid arthritis and psoriatic arthritis is that joint pain and stiffness and from RA usually affects the same joints on both sides of the body (symmetrical) and tends to occur in the small joints, such as those joints at the base of the fingers, the middle of the fingers, and the base of the toes, or may occur in a single, large joint, such as the knee or shoulder, or it may shift from one joint to another.

In psoriatic arthritis, joint pain, swelling, and stiffness is often on one side of the body and commonly occurs in large joints of lower extremities such as the knees and ankles, though it can affect any joint. 

Other symptoms that may accompany joint symptoms of rheumatoid arthritis and psoriatic arthritis include: 

  • Reduced range of motion in the joints
  • Fatigue/tiredness 
  • Pain and stiffness of the neck

Other symptoms of rheumatoid arthritis may include:

  • Muscle pain
  • Low-grade fever
  • Weight loss
  • Numbness and tingling in the hands or feet
  • Feeling unwell (malaise) 
  • Carpal tunnel syndrome
  • Finger deformities/bent fingers 
  • Standing and walking with weight on the heels
  • Swelling and redness of the top of the foot
  • Pain in the heel
  • Difficulty bending the knee 
  • “Baker's cyst” (a fluid-filled cyst in the space at the back of the knee)
  • Difficulty walking
  • Hoarseness and difficulty breathing
  • Bone loss — decreased bone density
  • Muscle weakness
  • Skin problems — rheumatoid nodules (painless lumps that appear beneath the skin) 
  • Eye problems — eye redness, pain, and vision problems
  • Lung disease — shortness of breath and a dry cough
  • Pericarditis — inflammation of the tissue around the heart that can cause chest pain and difficulty breathing
  • Vasculitis — inflammation of the blood vessels
  • Sjögren's syndrome — causes dry eyes and dry mouth

Other symptoms of psoriatic arthritis may include:

  • Pain is worse in the morning or after resting
  • Pain and stiffness lower back
  • Back, hip, and shoulder pain
  • Heel pain and foot pain 
  • Skin symptoms 
    • Skin rash (psoriasis)
    • Red patches of skin with silvery scales (plaques)
      • Commonly appears on the scalp, elbows, knees, and around the ears
    • Skin redness and warmth 
    • Scaly and itchy skin
    • Thickening skin
  • Sausage-like swelling of fingers and/or toes
  • Nails separate from nail bed
  • Pitted, crumbling nails
  • Eye inflammation such as pink eye (conjunctivitis)

What Is Rheumatoid Arthritis vs. Psoriatic Arthritis?

Arthritis describes over 100 different conditions that involve inflammation of any part of a joint, including the joint lining (synovium), cartilage, bones, and supporting tissues. Arthritis may affect one, a few, or many joints throughout the body.

Two common types of arthritis include:

  • Rheumatoid arthritis (RA)
    • A chronic autoimmune disorder characterized by persistent joint pain, swelling, and stiffness
    • Can also affect the skin, heart, lungs, and eyes
    • Differs from some other forms of arthritis because it affects both sides of the body
  • Psoriatic arthritis
    • A type of inflammatory arthritis that may develop in people with psoriasis, a chronic autoimmune skin condition that causes fast skin cell growth and renewal
    • Can affect any joint, but commonly occurs in large joints of the lower extremities such as the knees and ankles

What Causes Rheumatoid Arthritis vs. Psoriatic Arthritis?

The causes of rheumatoid arthritis and psoriatic arthritis are unknown; however, genetic factors seem to increase the chances of developing both conditions. People with a relative who has RA have an increased risk of developing the condition and about 40% of people with psoriatic arthritis have family members with psoriasis or psoriatic arthritis. 

Risk factors for developing rheumatoid arthritis include:

  • Age: middle-aged or older
  • Female sex: twice as likely as men to develop RA

Triggers that increase the chances a susceptible person will develop rheumatoid arthritis include:

It is thought that in addition to genetic factors, immunologic and environmental factors play a role in the development of psoriatic arthritis.

How Is Rheumatoid Arthritis vs. Psoriatic Arthritis Diagnosed?

Both rheumatoid arthritis and psoriatic arthritis are diagnosed with a medical history and physical examination, along with laboratory and imaging tests.

Tests used to diagnose arthritis include: 

Joint aspiration and analysis of synovial fluid may also be indicated.

A diagnosis of psoriatic arthritis also includes a skin examination to check for signs of psoriasis, along with tests to help diagnose psoriatic arthritis or to rule out other conditions that have similar symptoms to psoriatic arthritis. 

What Is the Treatment for Rheumatoid Arthritis vs. Psoriatic Arthritis?

Medications used to treat both rheumatoid arthritis and psoriatic arthritis may include:

  • Nonbiologic disease-modifying antirheumatic drugs (DMARDS) 
  • Biologic tumor necrosis factor (TNF)-inhibiting DMARDs 
  • Biologic non-TNF DMARDs 
  • Corticosteroids 
  • Nonsteroidal anti-inflammatory drugs (NSAIDs) 
  • Pain relievers (analgesics)
  • Topical skin products

Other therapies for rheumatoid arthritis include:

  • Heat and cold therapies 
  • Orthotics and splints 
  • Physical therapy and exercise 
  • Occupational therapy 
  • Adaptive equipment 
  • Joint-protection education 
  • Energy-conservation education 
  • Surgery

Other therapies for psoriatic arthritis include:

  • Immunosuppressants such as cyclosporine, for severe cases that do not respond to other systemic treatments
Reviewed on 3/28/2022
References
Image Source: iStock Images

https://www.uptodate.com/contents/arthritis-beyond-the-basics?search=Arthritis&source=search_result&selectedTitle=9~150&usage_type=default&display_rank=9

https://www.cdc.gov/arthritis/basics/types.html

https://emedicine.medscape.com/article/331715-overview

https://www.uptodate.com/contents/rheumatoid-arthritis-symptoms-and-diagnosis-beyond-the-basics?search=rheumatoid%20arthritis&source=search_result&selectedTitle=5~150&usage_type=default&display_rank=5

https://www.uptodate.com/contents/rheumatoid-arthritis-treatment-beyond-the-basics?search=rheumatoid%20arthritis&topicRef=512&source=see_link

https://www.psoriasis.org/

https://www.niams.nih.gov/Health_Info/Psoriatic_Arthritis/default.asp

https://www.uptodate.com/contents/psoriatic-arthritis-beyond-the-basics

https://creakyjoints.org/

https://www.arthritis.org/

https://www.ncbi.nlm.nih.gov/books/NBK115127/