Patients with diabetes are at significantly increased risk of developing foot ulcers. Combination of diabetes and foot ulceration remains the main cause of amputations in diabetic patients. The main changes affecting diabetic feet are:
- Reduced amount of blood and oxygen reaching the feet. This problem is known as Peripheral Vascular Disease and relates to either very narrow or blocked arteries in patients’ lower limbs.
- Reduced sensation in diabetic feet (Peripheral Neuropathy). This condition remains the most common change and represents itself as a significant numbness affecting feet in diabetes (Sensory Neuropathy). Thus, patients are not able to feel pressure applied to their feet causing them to develop pressure points and subsequent ulcers.
- Altered nerve function can also lead towards changes affecting small muscles in patients’ feet (Motor Neuropathy) and subsequent abnormality in the foot shape. This then causes development of pressure areas where ulcers will commonly develop.
- Neuropathy in diabetes changes the skin quality making it dry and prone to cracking (Autonomic Neuropathy). The cracked skin acts as an entry point for bacteria. Subsequently infections develop (Diabetic Foot Infections). If left untreated or when treatment is delayed, foot infections in diabetics can result in a rapid spread into healthy parts of the foot causing serious damage to small blood vessels and tissue death (necrosis or gangrene). Consequently, patients may require minor or major amputations. In advanced cases, local foot infection can result in generalised spread called sepsis. This condition can be life threatening.
Early detection and treatment of diabetic foot ulcers significantly reduces the risk of amputation; however, many patients fail to recognise when they have an ulcer due to the damaged nerves caused by their diabetes (Peripheral Neuropathy). This remains the most common reason for delays in treatment. It is of paramount importance to provide all patients with diabetes with adequate education regarding foot care and involve podiatrists from early on.
There are three distinct groups of diabetic foot ulcers:
Arterial ulcers are often located in the foot or higher up on the lower leg or back of the leg. These are often painful and deep, with unhealthy tissue at the base.
Treatment of poor blood supply significantly increases chances of ulcer healing. Without that ulcers are very unlikely to heal and the risk of amputation is high.
Neuropathic ulcers are generally located on the weight-bearing areas of the foot, such as the heel, surface of the foot, particularly the top of toes and the metatarsal heads (the plantar surface of the feet where toes are joining the foot). These are usually painless unless infection is present. The main part of the treatment is to remove ongoing pressure exposure (pressure off loading).
Neuro-ischaemic ulcers are generally seen on the margins of the foot, and can also develop on the tips of the toes and around the back of the heel. Those ulcers are a direct result of poor blood supply and impaired sensation affecting diabetic feet.