In all likelihood, if you have "beardruff" (a word I invented for convenience's sake), you probably also have dandruff and have by now discovered a shampoo or some other product which controls it. That product will also control beardruff in most cases.
Source: wiktionary
This can give you tons of issues with dry skin, itchiness, and the infamous “beardruff”.
Source: wiktionary
‘Beardruff’ is a real thing, often more apparent in the first few months of beard growth. Everyone’s skin varies. It takes time for the natural oils of your face to adjust to the new environment.
Source: wiktionary