title: Frequency and spectrum of myopathies in patients with psoriasis.
abstract: BACKGROUND
  Psoriasis is a T-cell-mediated skin disorder with uncommon extracutaneous manifestations. Rare patients with psoriasis and myopathy have been reported.
  
  
  METHODS
  We conducted a retrospective review of medical records of psoriasis patients seen at the Mayo Clinic during the period from January 1, 1996 to May 31, 2011. Patients who had pathologically confirmed myopathy or lymphocytic infiltrates in muscle were included.
  
  
  RESULTS
  Among 11,370 psoriasis patients, 13 had pathologically confirmed myopathies. Seventy percent were inflammatory myopathies, and 2 had focal inflammation in the muscle. Psoriasis preceded myopathy onset in two-thirds of the patients (median 14.7 years). Half of the patients had psoriatic arthritis; 60% had other autoimmune disorders. Patients who received anti-tumor necrosis factor-alpha (anti-TNF-α) therapy had a higher risk for developing myopathy or inflammation in muscle (odds ratio = 4.45).
  
  
  CONCLUSIONS
  Myopathy or inflammation in muscle affects an average of 1.32 of every 1000 psoriasis patients. Concomitant autoimmune disorders, psoriatic arthritis, and exposure to anti-TNF-α therapy may be associated with increased risk of developing myopathy in psoriasis patients.
authors.affiliation: Department of Neurology, University of Colorado Denver School of Medicine, Anschutz Medical Campus, 12631 East 17th Avenue, Aurora, Colorado, 80045, USA; Department of Neurology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
authors.forename: Teerin
authors.initials: T
authors.lastname: Liewluck
authors.forename: Floranne C
authors.initials: FC
authors.lastname: Ernste
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Tracy
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018501:Antirheumatic Agents / Q000009:adverse effects / Q000627:therapeutic use; D015535:Arthritis, Psoriatic / Q000453:epidemiology* / Q000209:etiology* / Q000276:immunology; D001327:Autoimmune Diseases / Q000453:epidemiology; D002648:Child; D015897:Comorbidity; D006801:Humans; D008875:Middle Aged; D009135:Muscular Diseases / Q000139:chemically induced / Q000453:epidemiology* / Q000276:immunology; D009220:Myositis / Q000139:chemically induced / Q000453:epidemiology / Q000276:immunology; D011565:Psoriasis / Q000150:complications* / Q000453:epidemiology* / Q000276:immunology; D012189:Retrospective Studies; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D055815:Young Adult
chemical_list: D018501:Antirheumatic Agents; D014409:Tumor Necrosis Factor-alpha
keywords: TNF-α antagonist; myopathy; myositis; psoriasis; psoriatic arthritis