Overview
A diabetic foot describes any pathology affecting the feet resulting from peripheral arterial disease and/or neuropathy secondary to diabetes mellitus.
Dysfunction of the sensory fibres in the feet can lead to the loss of protective mechanisms (e.g. pain in response to heat or pressure) leading to complications such as infection or a Charcot foot. Painful diabetic neuropathy can occur if nociceptive fibres are affected and problems with motor fibres can lead to an arched foot or toe-clawing.
Neuropathy and poor circulation can increase the risk of necessitating a foot amputation. Poor circulation can lead to delayed ulcer healing and slow recovery from infections.
Epidemiology
- Around 1/10 patients with diabetes have a foot ulcer at least once
- Up to 5 people with diabetes per 100,000 may need an amputation
Risk Factors
- Peripheral arterial disease
- Diabetic neuropathy
- Foot ulcers
- Previous amputation
- Charcot foot
Presentation
Features can be divided according to the underlying pathological mechanism:
- Features of diabetic neuropathy:
- Loss of sensation
- Neuropathic ulcers – usually on sites that experience pressure (e.g. the sole)
- Features of peripheral arterial disease:
- Absent foot pulses
- Intermittent claudication
- Reduced ankle-brachial pressure index (ABPI)
- Features of complications that may arise:
- Charcot foot (neuropathic joint)
- Ulceration
- Infection (e.g. cellulitis or in severe cases, osteomyelitis)
- Gangrene
Management
- Annual screening + consider referral to a local diabetic foot centre:
- Any patient with problems other than simple calluses should be referred
- Manage complications (e.g. neuropathic pain management if painful neuropathy develops)
Patient Advice
- Patients should be given oral and written advice on topics such as basic foot care, the importance of foot care, who to contact if advice is needed, footwear advice etc.
- Patients should be encouraged to examine their feet daily
Complications
- Foot ulcers
- Slow wound healing
- Cellulitis
- Osteomyelitis
- Charcot foot (neuropathic joint)
- Painful neuropathy
Prognosis
- Up to 70% of people die within 5 years of having an amputation. The high mortality rate is thought to be linked with associated cardiovascular disease. This risk can be mitigated by managing diabetes and cardiovascular disease effectively
