Psoriatic arthritis

Abstract

The occurrence of arthritis in patients with psoriasis has been recognized since the 19th century. However, psoriatic arthritis (PsA) was identified as a distinct entity primarily as a consequence of the efforts of the late Professor Verna Wright of Leeds, England, and his colleague Dr. John Moll of Sheffield, England (1). Epidemiological studies have noted that among patients with psoriasis, arthritis occurs in a higher prevalence than in the general population (2). Whereas the frequency of inflammatory arthritis in the general population is estimated to be 3% to 5%, among patients with psoriasis 7% to 42% have been identified as having PsA. Likewise, psoriasis occurs in a higher frequency among patients with arthritis (7%) than among the general population (1-3%). Although there are individuals who disagree with the identification of PsA as a distinct entity (3), it is now widely accepted that there is a specific form of arthritis associated with psoriasis (4).