Many medical conditions cause changes in the alignment of foot bones, creating calluses over time. Subtle at first, they can become as hard as toenails and stiff enough that one wrong step cracks through them deep into the underlying tissue.
Calluses are the adaptive product of 13 billion years of evolution. Some degree of callus formation can be normal and healthy on the soles of the feet. When feet lose normal sensation, callus production can become over-programmed. An abnormally tough outer layer of tissue forms in response to bone rubbing against the skin. The outer layer of tissue hardens until it starts to slide over and separate from the supporting tissue between the skin and the misplaced or misshapen bone. The separated layers blister and can progress to ulcers.
Loss of feeling may leave the foot owner unaware of the problem until significant tissue damage has happened. Recognition of wetness or staining on socks or shoes may be the first clue that there is a problem. This problem is not just about laundry. Patients with decreased feeling in their feet who develop a foot ulcer are at high risk for permanent injury. Without proper care, half will have an amputation within a year, and half will be dead from complications within 5 years.
Early recognition and intervention are critical to avoiding catastrophic outcomes. Patients in this situation commonly have co-existing artery or venous disease, both of which further complicate ulcer resolution. Ulcer care requires not only attention to associated skin and bone infection, but also adjustment of footwear. Temporary or permanent shoe or shoe liner modification to change the wear pattern on the foot is a critical part of management. Your wound consultant may refer your patient to an orthotist (shoe insert maker) to optimize a shoe gear solution.
Learning to do SELF shoe and foot exam EARLY in the course of diseases that typically lead to peripheral sensation loss can be a life- and limb- saving habit for your patient. There is in my office a collection of cat toys, bottle tops, extra socks, and even a pair of scissors that have been discovered in patient shoes. These treasures speak to the silent booby traps that lurk in the depths of un-examined foot gear.
In conclusion, take the plunge. Reaching into a patient’s shoe may be the key to keeping his toes and feet attached.