Difference between revisions of "Dermatomyositis"

(Differential Diagnosis)
Line 31: Line 31:
*Limb Girdle Muscular Dystrophy
*Limb Girdle Muscular Dystrophy
*[[Myesthenia Gravis]]
*[[Myasthenia Gravis]]
*Viral myositis
*Viral myositis

Revision as of 18:38, 25 March 2014


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

Clinical Features


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


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


  1. Cardiac (cardiomyopathy)
  2. High association with malignancy
  3. Interstial lung disease

Differential Diagnosis


  • CK
  • ANA
  • Chem for creatinine
  • Troponin, can involve myocardium
  • EKG
  • Bedside PFTs (FEV1 and FVC)
  • UA for myoglobin
  • Consider malignancies


  • Severe disease: Respiratory muscle symptoms of CHF
    • Methylprednisolone 1000mg/day x 3 days
  • Mild disease: Prednisone 1mg/kg/day (up to 80mg/day)
    • Taper after 6-8 weeks


  • Admit to monitored bed for CHF symptoms, respiratory muscle weakness
  • Admit for dysphagia/aspiration risk
  • Out patient follow up with muscle biopsy for others

See Also

  • Weakness
  • Polymyositis
  • SLE
  • Rheumatoid arthritis


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