title: Misdiagnosis in fibromyalgia: a multicentre study.
abstract: BACKGROUND
  Fibromyalgia (FM) is the second most common cause of visits to rheumatologists after osteoarthritis, and may be difficult to diagnose in many patients. It is associated with various rheumatic disorders such as rheumatoid arthritis, spondyloarthropathies (SpA) and connective tissue disease (CTD), and a late diagnosis or misdiagnosis is a common and underestimated problem.
  
  
  OBJECTIVE
  The aim of this study was to investigate the 'underdiagnosis' of FM, and which rheumatic diseases tend to be confused with it.
  
  
  METHODS
  The following data were collected at baseline: symptoms, disease duration, physical examination findings, previous and current investigations and management, laboratory tests, tender point count, tender and swollen joint counts, and spinal pain. The clinimetric evaluation included the Fibromyalgia Impact Questionnaire (FIQ) and Fibromyalgia Assessment Status (FAS).
  
  
  RESULTS
  The study population consisted of 427 outpatients (418 females and 9 males; mean age 49.3 years; mean disease duration 8.5 years). Fifty-seven patients (13.3%) had been previously misdiagnosed as having other musculoskeletal disorders (MSDs); 370 patients had been previous correctly diagnosed as having FM, or were diagnosed as having it during the course of the study. The FM and MSD groups were comparable in terms of demographic data and referral patterns. Disease duration was longer and the erythrocyte sedimentation rate was higher in the MSD patients, who also had less severe FIQ and lower pain visual analogue scale scores. Moreover, the FIQ and FAS scores correlated in the MS group.
  
  
  CONCLUSIONS
  The findings of this study suggest that, although FM is a wellknown clinical entity, differential diagnosis with SpA, CTD and inflammatory arthritis can still be a challenge for rheumatologists and general practitioners.
authors.affiliation: Department of Internal Medicine and Medical Specialities, Sapienza University of Rome, Rome, Italy. manuela.difranco@uniroma1.it
authors.forename: M
authors.initials: M
authors.lastname: Di Franco
authors.forename: C
authors.initials: C
authors.lastname: Iannuccelli
authors.forename: L
authors.initials: L
authors.lastname: Bazzichi
authors.forename: F
authors.initials: F
authors.lastname: Atzeni
authors.forename: A
authors.initials: A
authors.lastname: Consensi
authors.forename: F
authors.initials: F
authors.lastname: Salaffi
authors.forename: M
authors.initials: M
authors.lastname: Pietropaolo
authors.forename: C
authors.initials: C
authors.lastname: Alessandri
authors.forename: S
authors.initials: S
authors.lastname: Basili
authors.forename: M
authors.initials: M
authors.lastname: Olivieri
authors.forename: S
authors.initials: S
authors.lastname: Bombardieri
authors.forename: G
authors.initials: G
authors.lastname: Valesini
authors.forename: P
authors.initials: P
authors.lastname: Sarzi-Puttini
mesh_terms: D001799:Blood Sedimentation; D059350:Chronic Pain / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D003937:Diagnosis, Differential; D003951:Diagnostic Errors; D005260:Female; D005356:Fibromyalgia / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D006304:Health Status; D006801:Humans; D006930:Hyperalgesia / Q000175:diagnosis / Q000503:physiopathology; D007596:Joints / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009140:Musculoskeletal Diseases / Q000175:diagnosis; D010147:Pain Measurement; D010173:Palpation; D018434:Sickness Impact Profile; D013577:Syndrome