Seborrheic dermatitis is a common, noncontagious, easy-to-manage skin condition. This type of dermatitis causes itchy red patches and greasy scales on your skin along with white or yellow crusty or powdery flakes on your scalp. “Seborrheic” refers to the “sebaceous” glands while “derm” means “skin.”
https://my.clevelandclinic.org/health/diseases/14403-seborrheic-dermatitis

