title: Clinical manifestation, prevalence and prognosis of sarcoid arthropathy. A nationwide study: the Icelandic Sarcoidosis Study.
abstract: OBJECTIVE
  The Icelandic Sarcoidosis Study (ISS) contains all tissue-verified cases of sarcoidosis in Iceland since 1981. The present study has extended registration and verification to the start of 2004, thus covering over 23 years and a total of 234 cases. The aim of this study was to elucidate the prevalence, clinical manifestation and long-term prognosis of sarcoid arthritis in this unselected nationwide cohort. The presence of joint or muscle symptoms was registered in 20% of these cases.
  
  
  METHODS
  We used a questionnaire to register the lung and joint symptoms and all participants were offered a clinical evaluation with standardized interview and physical examination, including a count of the number of painful and/or inflamed joints.
  
  
  RESULTS
  Forty-seven (20%) of the 234 individuals in the ISS reported skeletal symptoms. In thirty-nine cases (17%) it was possible to confirm a history of inflammatory joint disorder. The mean age was 45 years: women 46 years (30-66), men 43 years (28-66). In 82% of the cases one or both ankles were involved. In 22 or 56% of the cases (13 female and 9 male) reliable data on the disease course were obtained; 87% of the patients had full recovery in less than 6 months, while 13% of the patients (all female) experienced chronic arthritic disease.
  
  
  CONCLUSIONS
  Our nationwide-based data confirmed that around a fifth of all those diagnosed with sarcoidosis will develop joint symptoms associated with their sarcoidosis, most usually in the ankle. The prognosis is favourable, but a subgroup of female patients may develop chronic polyarthritis. It is urgent to study further in detail the risk factors for a chronic arthritic condition in sarcoidosis; thus, it would be possible to offer those at risk of arthritis modifying anti-rheumatic treatment in the early phase of their disease course.
authors.affiliation: Centre for Rheumatology Research, Landspitali-University Hospital, Reykjavik, Iceland.
authors.forename: Dyrleif
authors.initials: D
authors.lastname: Petursdottir
authors.forename: Sigridur O
authors.initials: SO
authors.lastname: Haraldsdottir
authors.forename: Thorarinn
authors.initials: T
authors.lastname: Gislason
authors.forename: Bjorn
authors.initials: B
authors.lastname: Gudbjornsson
mesh_terms: D000328:Adult; D000368:Aged; D001168:Arthritis / Q000175:diagnosis / Q000453:epidemiology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011379:Prognosis; D012042:Registries; D012507:Sarcoidosis / Q000175:diagnosis / Q000453:epidemiology*; D011795:Surveys and Questionnaires