Greasy Dandruff or Steatoid Pityriasis: Seborrhic scale is the medical term for greasy dandruff. It has grayish or yellowish oily flakes usually found on the front of the scalp. The presence of oily flakes may be due to the existence of sebhorrea, which may result from dry dandruff or it may appear spontaneously.
If you have product build up you’ll typically have a film of residue on the scalp and hair. The flakes will be white and powdery as opposed to the grainy dandruff you get from a dry scalp, the yellow crusty oily shampoo from seb derm and the silvery scaly dandruff from scalp psoriasis.