Dermatomyositis

Revision as of 13:49, 20 July 2015 by Rossdonaldson1 (talk | contribs) (Differential Diagnosis)

Background

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

Clinical Features

Muscular

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

Dermatologic

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

Other

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

Differential Diagnosis

Weakness

Diagnosis

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

Management

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

Disposition

  • 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

References