Diabetes is a metabolic disease that is characterized by increased blood sugar or hyperglycemia. It can occur due to derangements in insulin secretion, action or both. This increased blood sugar state can affect different organ systems which include blood vessels, eyes, heart, nerves, kidneys, and foot. Long standing diabetes is known to cause damage, dysfunction, and failure of these organs.
How diabetes affects the foot?
Diabetes can cause micro vascular and macro vascular complications. In the foot diabetes can lead to diabetic neuropathy and peripheral vascular disease. About 10% of patients develop foot ulcers due to these complications. Uncontrolled diabetes and chronically raised sugar levels damage the ability to sense pain and temperature leading to diabetic neuropathy. In 90% of the patients distal symmetrical polyneuropathy (DSPN) is the commonest form of sensory diabetic neuropathy (Tesfaye, Boulton and Dickenson, 2013). Peripheral vascular disease affects the blood circulation to the extremities and because of low blood flow the infection risks are greater. This can lead to gangrene and ulceration. Due to severe ischemia secondary to these mechanisms patients can be completely asymptomatic. (Figure 2) This highlights the importance of regular foot screening in diabetics.
Global burden of diabetes
The International Diabetes Federation estimated that 425 million people in the world are affected by diabetes of which 46% are undiagnosed. By the year 2045 this figure is expected to rise to 629 million.
What is screening?
According to WHO “Screening is defined as the presumptive identification of unrecognised disease in an apparently healthy, asymptomatic population by means of tests, examinations or other procedures that can be applied rapidly and easily to the target population.”
The lifetime risk of a person with diabetes developing a foot ulcer could be as high as 25% (Singh, 2005). Poor diabetic control and management of diabetic foot complications result in amputation. (New et al., 1998) says that the relative risk of amputation associated with all types of diabetes is 13 times that of non-diabetics. Thus, foot screening is mandatory in diabetics and should be done at regular intervals.
Goals of screening:
Prevention and or early detection, of diabetic foot complications
Appropriate treatment and management
Reduce progression to amputation
When to screen? (NICE) (2015), (SIGN) (2017)
At diagnosis
Annually there after
If the patients notice any new/significant change
How to screen?
Validated foot screening questionnaire
Inspection
Sensory testing
Palpation of peripheral pulses
Check for foot deformities and callus
Previous foot ulcerations/ Gangrene
Screening should include conventional clinical examination, history, agreement on treatment regimen/ risk stratification, education on diabetic foot and rapid referral to appropriate specialist if needed. (NICE) (2015), (SIGN) (2017)
History
Detailed personal and diabetic history (age, gender, ethnicity, duration, medication, blood sugar control, symptoms of hyperglycemia, hypoglycaemia, ischemia and neuropathy)
Previous and current foot complications (repetitive minor trauma, use of over the counter medications)
Detailed medical and surgical history (Rheumatoid arthritis, Renal disease, Cardiovascular disease, any surgeries including amputation, peripheral vascular disease)
Social history (Managing daily activities, physical exercise, smoking, alcoholism)
Examination:
Skin over the foot (Colour, pain, abrasion, ulceration)
Neuropathy (using graduated tuning fork, thermal discrimination devices, 10g monofilaments, or vibration perception thresholds (Young et al., 1994) (Abbott et al., 1998)
Peripheral vascular disease (palpation of peripheral pulses preferred for screening, ankle brachial pressure index can be falsely high in patients with elevated systolic pressures)
Foot deformities (hallux valgus, hallux rigidus and hammer toes, claw toes, ankle equinus, high arch and calluses)
Appropriate foot wear
Education
Appropriate education about the disease and complications has yielded both short term and long-term improvement amidst the patients (Valk, Kriegsman and Assendelft, 2002).
Considering factors such as ethnicity and age when educating patients are important.
Self-care and monitoring, good foot hygiene, nail care, self-examination and use of moisturisers
Explain the danger signs such as blood-stained callous, skin injuries and infections
Dangers of neglect should also be communicated to the patient
Foot wear advice
Appropriate referral
Supervision of a multidisciplinary diabetic foot care team (specialist podiatrists, orthotist, nurses with training in diabetic wound care, diabetes physicians, vascular surgeons, interventional radiologists and microbiologists.)
Onward referrals to, and supervision of treatment by necessary specialists
For screening programmes to run effectively access to specialist services must be rapid, and there should be good communication between the primary and secondary care providers
Conclusion
The global burden of diabetes is on the rise, this is mostly attributed to the increasing population, life expectancy and modification of lifestyle including urbanisation. It is thus imperative to introduce a uniform screening and management guideline to prevent diabetic complications (Formosa, Gatt and Chockalingam, 2016).
The famous Scottish poet Thomas Campbell once wrote, “Coming events cast their shadows before.” Proper screening and patient education with prompt and appropriate referral can go a long way in minimising the impact of diabetic foot complications.
BIBLIOGRAPHY
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