A foot that has an open sore that isn't healing should be evaluated by a podiatrist or other physician for diagnosis and treatment. If the wound has been present for
a while, it needs medical care both in order to avoid infection and in order to see what the underlying cause might be.
Some people tend to ignore these wounds, figuring they'll eventually clear up. But an open foot sore that won't heal can be a sign of diabetes, poor circulation, or infection, which are all common conditions among older adults. And they're not likely to go away -- in fact, the problem is likely to get worse.
Both diabetics and people with undiagnosed diabetes, for example, often develop sores because they lose a degree of feeling in their feet. So they don't notice when an ill-fitting shoe rubs against their foot or ankle, or when they step on a pebble or scrape their instep. They also may not notice when a callus builds up and breaks down the skin underneath (one of the more common causes of a foot wound, known as a pedal ulcer).
Figuring out the cause for persistent foot problems is important. In the case of diabetes, the person needs regular, ongoing foot care by a podiatrist or other physician to avoid further infections.