Diabetic Foot

Keypoints

1. Patients with diabetic foot may present as an emergency with sepsis (with or without ischemia), they may also present with tissue loss.

2. A prompt diagnosis, clear pathway, management plan as well as urgent surgical intervention will cutback complications and reduce the risk of amputation.

3. Multidisciplinary team approach is inevitable, as these conditions may be life threatening.

Epidemiology

The global prevalence of Diabetes Mellitus is 5.1% and is constantly rising. It is anticipated to be 7.7% by 20301. It is calculated that 15% - 25% of Diabetic patients will suffer from diabetic foot infection and ulceration. Whilst 60–80% of them will eventually heal, 5–24% will end with amputation.

Pathogenesis of foot problems

Neuropathy:

Many factors contribute to the development of diabetic foot. The main factors are peripheral neuropathy and peripheral vascular disease.

More than 60% of foot ulcers are predominantly due to primary neuropathy. This neuropathy affects all components of the nervous system: sensory, motor fibers, and autonomic system.

Sensory neuropathy affects both type A myelin fibers which is responsible for proprioception and pressure sensation and type C sensory fibers which is responsible for pain.

Loss of the protective sensation increases the risk of foot ulceration. Skin damage following any minor trauma will lead to foot infection and abscess formation that eventually leads to ulceration.

Motor neuropathy leads to atrophy of the interosseous and lumbricales muscles that lead to claw deformity of the toes and foot arch. These deformities lead to areas of high pressure at the head of the metatarsal bones that may not be noticed by patients as they usually have sensory loss.

The autonomic neuropathy leads to altered blood flow regulation and diminished sweating which is responsible for dry skin and fissures, consequently patient’s feet will be prone to infection and ulcers.

Arterial Insufficiency

Although diabetic patients have warm swollen feet, they have reduced capillary flow as result of the microangiopathy which causes arteriovenous shunts.

Atherosclerosis in diabetic patients affects the crural vessels rather than the proximal vessels. The compromised blood flow to the feet may result in an ischemic ulcer or gangrene.

Management

a. Evaluation

Problems with diabetic foot can be serious, not only it can lead to limb loss but can also be life threatening.

Patients may present with symptoms and signs limited to the foot or with systemic problems.

A detailed patient history including history of any recent trauma or systemic disease such as renal or cardiovascular problems should be taken. The diagnosis is usually reached by a high clinical suspicion through the history and physical examination.