title: Psoriatic arthritis: An assessment of clinical, biochemical and radiological features in a single-centre South African cohort.
abstract: BACKGROUND
  Although psoriatic arthritis (PsA) is a well-documented clinical entity, epidemiological, clinical and radiological studies of South African (SA) patients are scarce.
  
  
  OBJECTIVE
  To assess clinical, biochemical and radiological features in a single-centre SA cohort.
  
  
  METHODS
  We conducted a prospective assessment of the clinical, biochemical and radiological features of 384 consecutive patients with PsA seen at the rheumatology clinic at Prince Mshiyeni Memorial Hospital, Durban, SA, between January 2007 and December 2013. Patients were assessed at enrolment and 6 months after enrolment. They were classified into five groups as described by Moll and Wright, being entered into the group that best described the clinical manifestations. Clinicopathological characteristics recorded at enrolment were age at the time of examination, racial background, personal and family medical history, age and symptoms at the onset of PsA, pattern of joint involvement, joint pain, and the relationship between joint pain and the onset of PsA.
  
  
  RESULTS
  Of the patients, 59.1% had a polyarticular presentation indistinguishable from rheumatoid arthritis, 19.0% had distal interphalangeal involvement, 9.1% had spondyloarthropathy, 11.9% had oligoarthritis and 0.9% had arthritis mutilans. The epidemiological trends (male/female ratio 1.45:1, mean age at onset of arthritis 50.2 (standard deviation 11.8) years, female preponderance in the polyarticular group and male preponderance in the spondyloarthropathy and oligoarticular groups) were similar to trends published elsewhere. A notable characteristic of our cohort was the complete absence of black South Africans with PsA.
  
  
  CONCLUSIONS
  The complete absence of black South Africans with PsA is interesting. We anticipate that our findings will prompt genetic studies to isolate both protective and susceptibility genes for further elucidating PsA.
authors.affiliation: Department of Internal Medicine, Prince Mshiyeni Memorial Hospital and School of Clinical Medicine, College of Health Sciences, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa; Division of Clinical Immunology and Rheumatology, Academic Medical Centre, University of Amsterdam, Netherlands. maharaja30@ukzn.ac.za.
authors.forename: Ajesh Basantharan
authors.initials: AB
authors.lastname: Maharaj
authors.forename: Michelle
authors.initials: M
authors.lastname: Rajkaran
authors.forename: Jayandran
authors.initials: J
authors.lastname: Govender
authors.forename: Kasthurba
authors.initials: K
authors.lastname: Maharaj
authors.forename: Niek
authors.initials: N
authors.lastname: De Vries
authors.forename: Paul-Peter
authors.initials: PP
authors.lastname: Tak