Clinical investigations from the RACP

Investigating patients with a vasculitic rash

D Heyworth-Smith, John Quin



Investigations should be directed by accurate historical and clinical findings. Many cases are from a drug reaction, and removal of the drug allows resolution. However, a vasculitis rash may herald a serious underlying condition.

Key Points

  • Most vasculitic rashes are caused by small vessel vasculitis.
  • Many cases are related to a new medication – e.g. beta-lactam antibiotics, sulfonamides, allopurinol, phenytoin.
  • Infectious causes of a vasculitis must be excluded.
  • Urinalysis should always be obtained; if normal, concomitant renal vasculitis is unlikely.
  • Histological confirmation by skin biopsy is desirable.