Concise answer
Ordinary dandruff does not usually destroy hair follicles, but inflammation and repeated scratching can increase temporary shedding or breakage. Not every flaky scalp is simple dandruff.
Thick scale, marked redness, pain, crusting or sharply defined patches can indicate another scalp disorder that needs identification.
Treating the correct scalp condition and avoiding aggressive scratching are more useful than repeatedly changing oils or shampoos.
When evaluation may help
Seek assessment when flaking is persistent, severe or accompanied by hair loss, tenderness, pus, broken hairs or spreading skin changes.