Diabetic foot

Background

• Diabetic foot problems = most common cause of non-traumatic limb amputation
• Life expectancy can be reduced by up to 15 years for people with diabetes
• 15% of people with diabetes will have a foot ulcer at some point in their lives

History

• Previous ulceration
• Previous amputation
• Symptoms of neuropathy (numbness, tingling, burning)
• Symptoms of vascular disease
• Onset of presenting problem
• Diabetes control and medication

Remove the patient’s shoes, socks and dressings and examine their feet

Both feet should be examined for:

• Dorsalis pedis pulse
• Posterior tibial pulse
• Temperature (cool-ischaemic) warm/hot (?infection)
• Peripheral sensory neuropathy

Look for:

• Discolouration in foot, Ulceration, Blisters, Necrosis
• Callus with signs of underlying extravasation, capillary leakage
• Red areas, Swelling, Infection/Cellulitis, ↑ body temperature, Flu-like symptoms
• Poor glycaemic control
• Pain in foot or leg even in presence of neuropathy

Remove the patient’s shoes, socks, bandages and dressings & examine their feet.

Specialist referral

If the following are present, obtain urgent advice from an appropriate specialist:

• Charcot’s arthropathy (which should be considered if deformity, redness or warmth are present.)
• Systemic sepsis
• Deep seated infection
• Limb ischaemia

If osteomyelitis is suspected

• If initial X-ray unconvincing, use MRI
• If MRI is contraindicated admit for white blood cell (WBC) scanning

Neuropathic ulcer

• May have heavy callus build up
• Found on weight bearing areas of foot
• Punched out appearance
• Usually pedal pulses can be palpated
• Can be deceptive as ulcer may penetrate to bone
• May present with localised/spreading infection
• Usually painless

Treatment

• Non adherent dressing to wound (± larger temporary shoe)
• Broad-spectrum antibiotic in presence of localised infection
• Urgent admission for bed rest and i/v antibiotics if spreading cellulitis
• X Ray for osteomyelitis
• Refer to podiatry for sharp debridement, wound/footwear assessment and multi-professional management

Neuro-ischaemic ulceration

Clinical signs

• Minimal callus build-up
• Ulcers often located where there may be pressure ±friction from footwear
• Pedal pulses non-palpable
• Often painful
• May be infected or appear necrotic/gangrenous

Treatment

• As above
• May require urgent vascular referral

Charcot's Neuro-arthropathy

Presenting symptoms

• Hot swollen foot, ± history of injury
• Peripheral sensory neuropathy
• Bounding foot pulses
• Differential diagnosis to eliminate osteomyelitis
• Early radiological signs absent
• Gold standard to Dx is technetium bone scan

Treatment

• Treat as though diagnosis confirmed while awaiting definitive diagnosis
• Refer to podiatry
• Non weight-bearing cast changed at weekly intervals until foot no longer hot and x-ray indicates resolution
• Too rapid mobilisation can be disastrous and lead to further bony changes
• It is essential to differentiate between Charcot’s and cellulitic foot
• Consider (IWGDF guideline) Vit. D supplements

Links

• Podiatrist CUH on site in OPD - Monday-Friday
• NICE Guideline 2011 - Diabetic foot problems - inpatient management
• International Working Group on the Diabetic Foot (IWGDF) https://iwgdfguidelines.org/