"Cradle cap", or infant seborrheic dermatitis, is when your baby has greasy scales on his or her scalp. With thick crusting of white and yellow, it can be quite noticeable, but it is actually very common and not serious. It can develop anytime in the first year of life but usually goes away on its own. However, there are some treatments to help it go away faster. This includes using baby oil or petroleum jelly to help soften the crusts before a bath, using medicated shampoos prescribed by your pediatrician, or using a topical medicine.