Callus (Hyperkeratosis)
According to NICE Guideline NG19 (Diabetic Foot Problems), in the absence of other risk factors, callus or hard skin is not in itself a risk factor. However, when combined with neuropathy or poor blood supply or a foot deformity, callus itself becomes a risk factor.
Many papers have demonstrated callus in a neuropathic foot can be a leading cause of foot ulcers.
What to look for
For correct identification of callus the Skin Scale can be used (see below). This photographic scale was created by Dr Matthew Young and Mike Townson. The article presenting the Skin Scale was published in 2014, The Diabetic Foot Journal.
Callus can occur wherever there is pressure beneath the foot. When grading the callus, use the worst piece of callus on the foot.
What to do
Urea is a Natural Moisturising Factor within human skin. It promotes water retention and helps maintain hydration levels. There is a wealth of good evidence supporting the use of urea in topical applications on the diabetic foot.
When using a product with urea as an active ingredient, if the % is below 20% then the product is regarded as a moisturiser, promoting hydration levels within the skin. If the % is above 20%, the product becomes keratolytic meaning it helps to safely remove callus.
In trials carried out in the Scottish Highlands and Whittington (London), patients’ callus was identified using the Skin Scale, were issued with
Dermatonics Heel Balm (25% urea) and asked to apply the Balm just Once A Day.
Optimal emollient treatment and prevention of diabetic foot complications – Bowen G, Bristow I, Chadwick P, Edmonds M, Kedia N, Leigh R, Welch D, Walker I, Warren T & Wylie D.
Diabetic Foot Journal Vol 24, March 2021
A round table discussion resulted in the following recommendations:
All people with diabetes and hyperkeratosis require daily application of urea-based cream for use on their feet.
All people with diabetes and peripheral neuropathy require daily application of urea-based cream for use on their feet.
All people with diabetes and hyperkeratosis & peripheral neuropathy require daily application of urea-based cream for use on their feet.
People with diabetes requiring urea-based emollient should have it made available via prescription.