title: The burden of psoriasis in Canada: insights from the pSoriasis Knowledge IN Canada (SKIN) survey.
abstract: BACKGROUND
  Although some data addressing the burden of illness associated with psoriasis and psoriatic arthritis (PsA) have been reported for American and European patient populations, similar data have been lacking for Canadians with these diseases.
  
  
  OBJECTIVE
  We sought to characterize the natural history of disease in a sample of Canadians with a history of moderate to severe psoriasis, with or without diagnosed PsA or other recognized comorbid conditions, and to identify factors that influenced their perception of psoriasis as a problem in their daily lives.
  
  
  METHODS
  A nationwide telephone survey, pSoriasis Knowledge IN Canada (SKIN), was conducted between April 30 and June 2, 2007, on 500 people who indicated that they had been diagnosed with psoriasis and that their skin lesions had at some time affected an area at least as large as three palms of their hand (3% of body surface area [BSA]).
  
  
  RESULTS
  The mean age at diagnosis for psoriasis among SKIN survey respondents was 28 years, with 31% (155 of 500) indicating that they developed the disease prior to age 18 years. At the time of the survey, 54% (269 of 500) of respondents were experiencing lesions affecting a BSA equivalent to at least three palms (3%). In response to questions on the burden of illness, 35% (176 of 500) of respondents indicated that they considered psoriasis to be a substantial problem in their daily life. Both affected BSA at the time of the survey and self-reported extent of skin involvement at the height of the condition (BSAmax) correlated with the perception of psoriasis as a substantial problem. Other subpopulations in which psoriasis was commonly identified as a substantial problem included women and individuals with diagnosed PsA. Whereas 18% (88 of 500) of respondents were diagnosed with PsA, the number who reported joint pain or stiffness was substantially higher (51%; 256 of 500), suggesting that some respondents may have had incipient or undiagnosed PsA.
  
  
  CONCLUSIONS
  This survey reveals that psoriasis, PsA, and their associated comorbidities impose a severe burden on the daily lives of Canadians with a history of moderate to severe psoriasis.
authors.affiliation: Centre for Dermatology, Markham, ON. derma@lynderma.com
authors.forename: Charles W
authors.initials: CW
authors.lastname: Lynde
authors.forename: Yves
authors.initials: Y
authors.lastname: Poulin
authors.forename: Lyn
authors.initials: L
authors.lastname: Guenther
authors.forename: Christine
authors.initials: C
authors.lastname: Jackson
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D002170:Canada / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D009017:Morbidity / Q000639:trends; D010353:Patient Education as Topic; D011159:Population Surveillance / Q000379:methods*; D011565:Psoriasis / Q000453:epidemiology*; D011788:Quality of Life; D012189:Retrospective Studies