07 Mar 2016
A simple, non-invasive 10-minute screening test called neuropad® that may help address the worryingly and stubbornly high incidence of foot ulcers and amputations is now available in the UK having been available for some time in Germany, Switzerland and Austria. Diabetes patients will now be able to check for nerve damage using a very simple home device which works by detecting sweat. It’s like an early-warning system for your feet.
The new stick-on pad changes colour from blue to pink when all is well, but remains blue or partially changes to pink, if there are problems with important nerve fibres in the feet. Diabetic neuropathy, which is damage to important nerves in the feet, is a common complication of poorly controlled diabetes. Typically, it affects the extremities – when it is known as peripheral diabetic neuropathy – and is estimated to affect up to 50 per cent of all patients with diabetes. It occurs when high blood sugar levels damage special nerve fibres that modulate heat, blood flow and sweat function. Symptoms can include pain and numbness, but the main danger is that patients may not feel minor injuries, which can subsequently become infected or ulcerated. These wounds can be difficult to heal because diabetes also reduces blood flow to the feet. Infections can spread and cause tissue death or gangrene; it is estimated that every week, 100 people lose a foot or limb through diabetes. Detecting the condition of the feet at an early stage could mean that preventive action, such as checking the feet daily for signs of injury, use of a specialist foam moisturiser and better overall diabetes control can be taken.
Current checks may include a ‘nerve conduction’ test, or electromyography, where electrodes are inserted into the muscles to assess nerve function. However, this has to be carried out at a clinic by a health care professional such as a doctor, specialist nurse or podiatrist and may be painful. For the NHS, the equipment can be very expensive to acquire.
The new neuropad® screening test – which is designed specifically for the feet – is much simpler and can be carried out at home or in a clinical setting. It takes just ten minutes to complete and the results are typically unambiguous; blue to pink is normal, blue/pink or blue is not and patients should contact a member of their diabetes healthcare professional team or their GP for further investigation or referral.
The neuropad® screening test works on the basis that damage to the nerve fibres in the feet leads not only to a loss of sensation, but also a malfunctioning sweat system and, in turn, to unusually dry skin on the feet. The adhesive pad contains the blue salt anhydrous cobalt II chloride, which reacts and changes to pink when exposed to water.
The person applying the test simply has to remove their socks, allow each foot to adjust to room temperature and then apply a test pad to each foot, which is then kept in place for ten minutes. If there is little or no sweat present, there will be minimal or no colour change – clinical studies suggest that this strongly suggestive of early diabetic neuropathy.
The rationale behind the test is that the earlier a problem is identified, the better the chances that it can be treated through better overall diabetes control and also the moisturising of symptomatic dry feet to help keep them as healthy as possible.