Difference between revisions of "Dermatomyositis"

(Text replacement - "Category: Rheum" to "Category:Rheumatology")
(Text replacement - "EKG" to "ECG")
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*Chem for creatinine
*Chem for creatinine
*Troponin, can involve myocardium
*Troponin, can involve myocardium
*Bedside PFTs (FEV1 and FVC)
*Bedside PFTs (FEV1 and FVC)
*UA for myoglobin
*UA for myoglobin

Revision as of 17:18, 19 May 2016


  • Inflammatory myopathy
  • Affects proximal muscles > distal
  • Female:Male; 2:1
  • Peak incidence 40-50s

Clinical Features


  • Proximal greater than distal weakness
    • Deltoid and hip flexors
    • difficulty standing from a chair
  • Onset over months
  • Mild myalgias


  • Heliotrope rash on face scalp
  • Gottron's papules (rash on MCP, PIP, and DIP joints)
  • Shawl sign (rash above shoulders)


  • Cardiac (cardiomyopathy)
  • High association with malignancy
  • Interstial lung disease

Differential Diagnosis

  • Drug Induced Myopathies (Statins)



  • CK
  • ANA
  • Anti-Jo-1
  • Chem for creatinine
  • Troponin, can involve myocardium
  • ECG
  • Bedside PFTs (FEV1 and FVC)
  • UA for myoglobin
  • Consider malignancies


Mild disease

  • Prednisone 1mg/kg/day (up to 80mg/day)
    • Taper after 6-8 weeks

Severe disease

  • Respiratory muscle symptoms of CHF
    • Methylprednisolone 1000mg/day x 3 days


  • Admit to monitored bed for CHF symptoms, respiratory muscle weakness
  • Admit for dysphagia/aspiration risk
  • Out patient follow up with muscle biopsy for others
  • Very strongly associated with malignancy (~30%), especially:[1]
    • Ovarian
    • Lung
    • Pancreatic
    • Stomach
    • Colorectal
    • Lymphoma
    • Bladder

See Also


  1. Hill CL et al. Frequency of specific cancer types in dermatomyositis and polymyositis: a population-based study. Lancet. 2001 Jan 13;357(9250):96-100.