I think the jury is still out on this. In propecia trials they used nizoral too, and many men seem to have issues with dandruff/itching and inflammation. Most likely its related, but so far there is no concrete proof they are.
Does inflammation and itching happen to your beard or chest hair or body hair? Not normally. Id guess all these things the itching/dandruff do play some unknown role in male pattern baldness otherwise why is it so much more common in men than women?
The difference between men and women with rates of male pattern baldness, and hormone profiles is good circumstantial evidence that hormones and things like this are interconnected somehow even if we never understand how.