Diabetic Foot

Diabetic Foot Ulcers

Diabetic foot ulcers can be divided into:

  • Diabetic foot ulcers in Neuropathic Feet
  • Diabetic foot ulcers in ischaemic

 

Neuropathic Foot

  • Warm
  • Well perfused
  • Palpable pulses
  • Sweating is decreased
  • Skin may be dry and prone to fissures

Ischaemic Foot

  • Cool
  • Pulseless
  • Thin shiny skin
  • Often lacks hair
  • May be atrophy of subcutaneous tissues
  • Intermittent claudication and rest pain may be absent due to co-existing neuropathy

Diabetic Foot Infections

  • Common
  • Always serious
  • Can be minor – superifical paronychia or serious  – deep infection and gangrene

Other manifestations of infection include

  • Cellulitis
  • Myositis (inflammation of muscle)
  • Abscesses
  • Necrotising fasciitis
  • Septic Arthritis
  • Tendonitis
  • Osteomyelitis

Obviously, there’s a high risk of prolonged hospital stay and amputation with these infections

 

 

Diabetics are more prone to foot ulceration in view of they neuropathy, vascular insufficiency, and reduced neutrophil function.

Ulceration leads to..

underlying tissues are exposed to colonisation by pathogenic organisms

Because the inflammatory response is impaired the early signs of infection may be subtle.

Local Signs of Wound infection in diabetic feet are:

  • Granulation tissue that becomes increasingly friable
  • Yellow or grey moist tissues at the base of the ulcer
  • Purulent discharge
  • Unpleasant odour

Common Pathogens in Infective Diabetic foot

  • In previously untreated superficial ulcers
    • Aerobic gram positive – commonly
      • Staphlococcus Aureus and
      • Beta haemolytic Streptococci

 

  • In Patients who have recently received antibiotics or who have deep tissue involvement
    • Infection is usually a mixture
    • Aerobic gram positive
    • Serobic gram negative (eg E. Coli, Proteus, Klebsiella)
    • Anaerobic organisms (Bacteroides, Clostridium)

Methicillin-resistant Staphylococcus Aureus (MRSA) is more common in patients who have been hospitalised or have received antibiotic therapy (though it’s becoming more commonly community acquired).

If infection is suspected:

  • Send deep swabs for culture
  • Send tissue samples for culture
  • Start broad-spectrum antibiotics (which can be tailored according to swab results)
  • If there’s deep infection, abscess, cellulitis, gangrene or osteomyelitis – hospital admission

Indications for surgical intervention:

  • Large area of infected sloughy tissue
  • Localised fluctuance and expression of pus
  • Crepitus and gas in the soft tissue / x-rays
  • Purplish discolouration of the skin (indicating subcut necrosis)

If there’s osteomyelitis – surgical resection considered and antibiotics for 4-6weeks