After 30 years I have made enough mistakes for several people, so maybe I can spare you some of them.
Don’t miss Necrobiosis lipoidica diabeticorum.
Necrobiosis lipoidica diabeticorum (NLD) is a skin eruption that usually occurs on the shin in diabetic patients but it can be on many other body areas. It’s more common in women, more common after age 30, more common among people already diagnosed as diabetic, and more common among the insulin dependent diabetics. It’s also relatively rare in general with an incidence of only about 0.3% among diabetics. It can be the way diabetes or glucose intolerance presents.

The problem is that if you run a wound center, rare things are NOT rare. I feel like every day is an episode of CSI or “House.” It’s one of the things that makes wound care fascinating. Wounds are not a disease, they are a SYMPTOM of a disease.
This patient had been cared for somewhere else for many years. I’m not sure that it was ever really understood that she had NLD. The lesions look sort of “waxy”. It could remind you of pyoderma gangrenosum but it’s not as painful, perhaps because of the neuropathy, and so far, in all the patients I have seen, their transcutaneous oxygen or skin perfusion pressure is excellent. I won’t discuss treatment or the  theories of why it occurs, I just think it’s good to be reminded that we need to practice pattern recognition.

Start with getting the diagnosis right.