Skin and Wound Care

Diabetic Foot or Neuropathic Ulcer

Diabetic foot ulcers, or neuropathic ulcers, are caused by the loss of protective sensation in combination with structural changes and repeated trauma/pressure to the foot.1,2
Risk factors for developing peripheral neuropathy are1:
  • Poor glucose control
  • Smoking
  • Elevated triglycerides
  • Hypertension
  • High body mass index
Peripheral neuropathy is the degeneration of peripheral nerves. This involves2:
  • Sensory neuropathy: loss of sensation; client is unable to feel pain or pressure. Also called LOPS (loss of protective sensation)
  • Motor neuropathy: loss of intrinsic muscle; results in clawed toes and eventually foot drop; deformity 
  • Autonomic neuropathy: loss of autonomic function resulting in the absence of sweat and oil production, leaving skin dry and non-elastic
Loss of protective sensation, foot deformities, and limited joint mobility can result in abnormal biomechanical loading of the foot. This produces high mechanical stress in some areas, the response to which is usually thickened skin (callus). The callus then leads to a further increase in the loading of the foot, often with subcutaneous hemorrhage and eventually skin ulceration. Whatever the primary cause of ulceration, continued walking on the insensitive foot impairs healing of the ulcer.

Prevention

  1. Identify the at-risk foot
  2. Regularly inspect and examine the at-risk foot
  3. Educate the patient, family and health care providers
  4. Ensure routine wearing of appropriate footwear
  5. Treat risk factors for ulceration
  • Frequency of re-screen depends on the risk category for each client.
  • A comprehensive diabetic or neuropathic foot screening assessment must include:
    • Sensation: monofilament testing
    • Vascular status: TBIs, ABPIs, vascular studies
    • Deformity: structural changes to foot
    • Areas of pressure: when walking and with footwear
    • Footwear
    • Skin assessment: colour, temperature, presence of callus or edema

Improper footwear is a significant cause of ulcers and amputations.4 Due to the loss of protective sensation, clients are unable to feel pressure or trauma due to footwear.

A well-fitting shoe should provide support during the gait cycle and provide protection to the foot.3

Clinician Assessment4

  • Fit: the toe box should be large enough to prevent pressure on toes. The heel should be firm-fitting but not too tight. Length should be 1-2 cm longer than their foot and width should equal the widest part of the foot.5
  • Structure: shoes should have features that support the foot. Shoes should have Velcro® or laces. Shoes should not have seams or structures that would result in pressure or friction
  • Cushioning: shoes need enough cushioning to act as shock absorbers
  • General features: shoes should be made of breathable materials such as leather
  • Motion control: shoes should limit over-pronation (foot rolling inward and arch flattening)
  • Other: check for any foreign objects within the shoe
  • Footwear fit assessment:
    • Trace the clients bare foot on a piece of paper in one color pen, using a different colored pen trace the outline of the clients shoe over top of the bare foot tracing.
    • This is a quick way to help clients visualize the fit of their shoes in comparison to their feet.

Client Self-assessment for Footwear

  • Patients should check their shoes for foreign objects every time prior to putting on their shoes.
  • If there is no off-the-shelf footwear that can accommodate the foot (e.g., if the fit is poor due to foot deformity) or if there are signs of abnormal loading of the foot (e.g., callus, ulceration), refer the patient for special footwear (advice and/or construction), possibly including extra-depth shoes, custom-made shoes, insoles, or orthoses.5
  • Daily foot inspections: suggest using a mirror to see the bottoms of their feet
  • Proper nail care: cut nails straight across5, or use a nail file
  • Review the following practice5:
    • Avoid walking barefoot, in socks without footwear, or in thin-soled slippers, whether at home or outside
    • Do not wear shoes that are too tight, have rough edges or uneven seams
    • Visually inspect and manually feel inside all shoes before you put them on
    • Wear socks/stocking without seams (or with the seams inside out); do not wear tight or knee-high socks (compressive stocking should only be prescribed in collaboration with the foot care team), and change socks daily
    • Wash feet daily (with water temperature always below 37°C), and dry them carefully, especially between the toes
    • Do not use any kind of heater or a hot-water bottle to warm feet
    • Do not use chemical agents or plasters to remove corns and calluses; see the appropriate healthcare professional for these problems
    • Use emollients to lubricate dry skin, but not between the toes
    • Have your feet examined regularly by a healthcare professional
  • Treat any modifiable risk factors4:
    • glycemic level
    • smoking
    • activity
    • trauma
    • footwear
  • Removal of callus buildup 
  • Revascularization may be required

Management of a Diabetic foot Ulcer

D

Diabetes Management

  • Optimize blood glucose control
  • Co-morbidity management (e.g., blood pressure, lipids, smoking, kidney function, nutrition, smoking)
  • Consider psychosocial implications of diabetes 
Possible interventions:
  • Consult to DCM &/or endocrinologist
  • Smoking cessation program
  • Nutritional assessment and interventions 
  • Social work consult, community supports
F
Foot/Find the Cause
  • Determine the cause of ulcer and remove offending factor (e.g., footwear, self-care, burns or trauma)
  • Foot screening inspection
  • Assess for neuropathy 
  • Educate client on appropriate self-care

Possible interventions:

  • Assess footwear for foreign objects, signs of age (wear and tear)
  • Assess bone structure of foot for deformities
  • Self-care teaching examples: daily assessment of feet, wear white socks, check shoes prior to putting them on, do not soak feet, never walk without shoes 
U
Ulcer
  • Wound assessment 
  • Wound treatment plan: moisture balance, bacterial burden and debridement

Possible interventions:

  • Comprehensive wound assessment
  • Treatment plan: moisture management, decrease bacterial burden and remove necrotic tissue
V
Vascular Supply
  • Assess for blood flow: pulses, TBIs, NIVS, Doppler’s 
  • Clinical signs and symptoms of LEAD (Lower Extremity Arterial Disease)

Possible interventions:

  • Is there enough blood supply to heal?
  • Consult to vascular surgeon
I
Infection
  • Clinical signs and symptoms; big three for diabetics: pain in neuropathic foot, erratic blood glucose, and flu-like symptoms
  • Bacterial balance
  • Wound swabs, tissue/bone culture
  • Imaging
Possible interventions:
  • DFU infections are common and must be routinely assessed for
  • Evaluate the signs and symptoms, obtain specimens if required, select the appropriate antibiotics
  • Utilize topical antimicrobials if warranted by assessment 
  • Consult to infectious disease
P
Pressure 
  • Offloading devices
  • Decrease weight bearing activities
  • Appropriate footwear 
  • Pressure can be from foot deformity, inappropriate footwear, callus
Possible interventions:
  • Consult to pedorthist for offloading devices (e.g., casts - irremovable and removable, wound healing shoes, orthotics)
  • Non-weight bearing may be an appropriate strategy: wheelchair, crutches
S
Sharp Debridement 
  • Removal of callus and necrotic tissue in patients with adequate blood flow
Possible interventions:
  • Callus buildup around wound causes increased plantar pressures  
  • Necrotic tissue serves as a reservoir for bacteria

 

  • Pressure is a factor in 90% of diabetic plantar ulcers.4
  • Offloading is a key component of diabetic foot management, but there are significant challenges, including:
    • availability and cost of devices
    • impact on the patient's ability to work
  • Select an offloading option that works best for the patient’s lifestyle, ulcer and situation (e.g., work, finances, living environment)

Resources

References

1. British Columbia Provincial Nursing Skin and Wound Committee. (2012). Guideline: Assessment & treatment of diabetic and neuropathic ulcers in adults. Retrieved from: https://www.clwk.ca/buddydrive/file/guideline-diabetic-neuropathic-ulcers/

2. Elftman N. & Conlan E. (2012). Management of the neuropathic foot In C. Sussman & B. Bates-Jensen (Ed.), Wound Care A Collaborative Practice Manual for Health Professionals (pp. 325-367). Philadelphia, PA: Lippincott Williams & Wilkins.

3. Mahoney E. (2010). Diabetic foot ulcerations In J.M. Mcculloch & L.C. Kloth (Ed.), Wound Healing Evidenced-Based Management (pp. 213-230). Philadelphia, Pa: F.A. Davis Company.

4. Botros M., Kuhnke J., Embil J., Goettl K., Morin C., Parsons L., Scharfstein B., Somayaji R., Evans R. (2017) Best practice recommendations for the prevention and management of diabetic foot ulcers. In: Foundations of Best Practice for Skin and Wound Management. A supplement of Wound Care Canada

5. Schaper N.C., van Netten J.J., Apelqvist J., Bus S.A., Hinchliffe R.J., & Lipsky B.A. (2019). IWGDF Practical Guidelines on the Prevention and Management of Diabetic Foot Disease. Available from: https://iwgdfguidelines.org/wp-content/uploads/2019/05/01-IWGDF-practical-guidelines-2019.pdf