Management of complications in the chronically traumatised and infected groin are especially challenging. The IVDU groin will have chronic scarring and fibrosis with fistula formation from repeated arterial and venous puncture.

Complications in the IVDU Groin

• Oedema and lymphoedema (chronic trauma and infection).
  
• Scar tissue (chronic trauma and recurrent infection).
  
• Infection:
  
  
  
  • Abscess formation (may be prevascular).
    
  • Cellulitis.
    
  • Necrotising fasciitis.
  
  
• Pseudoaneurysm formation:
  
  
  
  • Infected (mycotic) versus non-infected.
    
  • Ruptured (massive haemorrhage) versus non-ruptured.
  
  
• Fistula formation (chronic traumatic injection).
  
• Venous thrombosis (proximal DVT):
  
  
  
  • Chronic venous fibrosis.
    
  • Valve destruction and chronic venous reflux.
    
  • Venous hypertension.
  
  
• Arterial thrombosis (acute, chronic, acute-on-chronic).
  
• Arterial stenosis.
  
• Distal embolisation (mycotic material, thrombus from aneurysm).
  
• Necrosis of overlying skin.

Microbiology

• The IVDU groin contains challenging and unusual microflora due to repeated trauma weakening tissue defences, use of unsterile needles, unsterile injected substance and repeated injection through unclean skin.
  
• Growth is often polymicrobial with unusual bacteria and fungi that can disseminate to distant sites (e.g. liver abscess, brain abscess and endocarditis).
  
• Gram negative anaerobic bacteria predominate (including bacteroides, E.coli and tetanus subspecies), but peptostreptococcus (G+ve) is also common.
  
• There is also a high prevalence of blood-borne viral infections including hepatitis B, C and HIV.
  
• Tuberculosis is more common amongst drug users.