Aetiology and incidence

Aetiology and incidence

• an estimated 5-7% of all people with psoriasis, and approximately 40% of those with extensive skin disease, have psoriatic arthritis (PsA)
• undiagnosed PsA may be prevalent because many asymptomatic people with psoriasis have radiological evidence of joint damage
• men and women are equally affected
• because of problems in definitively diagnosing PsA, there are few studies on its incidence and prevalence, and the results vary widely depending on the cohort studied and the diagnostic criteria used
  • PsA has a prevalence of between 0.1% and 1% (1)
  • may develop at any age including childhood period (2)
  • incidence peaks between the ages of 30 and 55 years(1)
• The condition has a genetic component:  
  • HLA-DR4 is a risk factor for psoriatic and rheumatoid arthritis
  • patients with psoriatic spondylitis share HLA-B27 with other spondylitic patients
  • the additional causal factors in psoriatic patients are unknown and may vary between patients

Reference:

• 1. . NICE (July 2006). Etanercept and infliximab for the treatment of adults with psoriatic arthritis
• 2. American Academy of Dermatology 2008. Guidelines of care for the management of psoriasis and psoriatic arthritis - Section Psoriatic arthritis: Overview and guidelines of care for treatment with an emphasis on the biologic