Some people with diabetes lose their perception of feeling in their feet. This is called Diabetic Peripheral Neuropathy (DPN) and is defined as
“the presence of symptoms and/or signs of peripheral nerve dysfunction in people with diabetes after exclusion of other causes” (Bolton 1998).
Many people will be unaware that any such problems exist and up to 50 % of people at diagnosis may present with some signs of neurological changes.
DPN can lead to various problems.
- Lose of protective sensation resulting in the inability to feel pain
- Change of shape of the foot such as clawing of the toes resulting in areas of increased pressure which may cause areas of callus especially under the metatarsal heads.
The simplest and most evidence based way to determine if an individual is suffering from DPN is to test them with a 10g monofilament.
First show the individual that the monofilament is not sharp by performing the test on the back of your hand and then on the individual’s forearm. The next stage is to inform the individual that you will be testing each foot with their eyes closed and they have to say yes each time they feel the monofilament touch their foot.
There are 5 areas tested on each foot. They are the apex of the 1st and 3rd toes, the 1st, 3rd and 5th metatarsal heads. These tests are carried out in a random fashion with the monofilament at a 90° angle to the foot. The monofilament showed be depressed with enough force to cause a bend in the monofilament and should be in contact with the skin for between 1 and 2 seconds. The monofilament should not be allowed to slide across the surface of the skin and areas of callus or any breaks in the skin should be avoided.
- If the individual can not feel more than 8/10 of the tested sites then they can be diagnosed as having PDN and this can put them at risk of developing a diabetic foot ulcer. Any such individual need to be in a managed treatment plan. All individuals identified as Moderate risk should receive an annual assessment by a podiatrist which should include screening and the checking of individuals risk status. This should then lead to the introduction or review of a treatment /management plan, including reinforcement of education, formulated in consultation with the individual and tailored to suit the individual’s needs.
