I don't know that I'd agree with that David. We can't always determine the etiology but we are still expected to document it's presence because it is an abnormality. Describing what you see (erythema, exudate type, exudate amount, odor, location, etc.) helps to paint a better picture of what is going on (unfortunately nurses often don't know the terminology). Following it up with a plan of care is key. If you found something, what is your plan to fix the situation?