A year and a half ago I wrote some thoughts and questions About Perfectionists. 

Since writing that Thought Post, I have read psychologists' views describing the linkages between anxiety and perfectionism. Psychologists, at least some of them, believe anxieties can build around thoughts about the need to perform work well. These thoughts are held until the anxieties 'take over' and the mindset becomes one of perfectionism. Criticism is a play here...in the perfectionist's mind. Perhaps, it appears to be self-criticism. However, it seems to me that 'self-criticism' does not develop in the absence of prior 'external criticism'. Likely, the external criticism began many years before perfectionism appeared. Excessive criticism of children by parents or other authority figures likely is the major contributor to if not the root cause of perfectionism. That external criticism might have been real. Or, I suppose, it could be perceived.

Then, as the saying goes, perception is reality...so, it likely doesn't make any difference if external criticism was real or perceived/imagined. What matters is criticisms have generated heightened anxieties and, over time, those heightened anxieties have gained a high level of control over the mind. And, the combinations of criticism and anxiety have led to perfectionism. 

That is plausible.

That provides some clues as to how leaders should react to perfectionism.

Leaders must take care when they observe perfectionism in action.

Leaders should avoid reactions/actions that could expand anxieties experienced by perfectionists. 

Leaders must understand they may need help from professionals who are trained to help people who experience excessive anxiety.