It affects the sebaceous (oily) regions of the scalp. It causes patches of greasy skin covered with itchy, crusty, powdery flakes. The flakes may be white or yellow. Scratching these spots can ...

Bumps on the scalp can be caused by other skin disorders such as folliculitis, scalp acne, or dandruff. They could also show up due to an allergic reaction to a product or skincare routine.