Myositis – Grade 2

Management escalation pathway

• Stop ICPI
• Start corticoids 1mg/kg after discussion with internist/rhumatologist/neuromuscular specialist, continue for at least 1 month even if clinical imporvement after 1 week. If needed add other immunsuppressants so corticoids can be tapered after one month
• If no improvement after 48h (pain or CK): increase to 2 mg/kg; if still no improvement 48h later, other immunosuppressants should be discussed with experienced organ specialist
• Consider IVIG (no reimbursment in Belgium) or bolus steroids if severe life threatening weakness, less evidence for plasma exchange

Assessment and Investigations

• In addition to analysis for grade I:
  • Perform EMG to evaluate myopathic features
  • Assesment of diaphragm motion: X ray and perform respiratory tests both in upright and horizontal position.
• Perform MRI of affected muscle
• Consider muscle biopsy before start steroids (should be done by experienced specialist)
• Analyze serology before start of steroids (ANF (+further subanalysis), myositis specific antibodies / myositis associated antibodies: according to local practice)
• Perform spirometry in order to assess restrictive syndrom (due to paralysis of intercostal muscles)