Psoriatic arthritis

Psoriatic arthritis

Psoriatic arthritis is a synovitis which occurs:

• in individuals with psoriasis but without serum rheumatoid factor (it is an inflammatory seronegative spondyloarthropathy) (1)
  
  
• in a person without psoriasis but with joint changes resembling those seen in rheumatoid arthritis the relationship between the skin and joint manifestations is unclear
  
  
• the symptoms occur simultaneously in around 20% of people with the disease (2)
  
  
• in 60% of people the psoriasis precedes the arthritis
  
  
• in 25%, the arthritis appears first
  
  
• people with severe arthritis can have little or no skin disease, and vice versa
  • flare-ups of symptoms do not necessarily coincide (1)

Psoriatic arthritis may mimic rheumatoid arthritis or ankylosing spondylitis.

Click here for images of psoriatic arthritis

Reference:

1. Ritchlin CT, Colbert RA, Gladman DD. Psoriatic Arthritis. N Engl J Med. 2017 May 25;376(21):2095-6.
2. Mease PJ, Gladman DD, Papp KA, et al. Prevalence of rheumatologist-diagnosed psoriatic arthritis in patients with psoriasis in European/North American dermatology clinics. J Am Acad Dermatol. 2013 Nov;69(5):729-35.