The exact cause of infant seborrheic dermatitis is unknown. Overproduction of your baby’s oil-producing sebaceous glands or a type of yeast in the oil may contribute to your baby’s condition. The glands are on the baby’s scalp. Scientists think the changing hormone levels in the mother’s body during pregnancy may cause a baby’s sebaceous glands to overproduce. Normal skin cells are naturally shed in a process called desquamation. However, the cells will remain stuck to the scalp if there is an abundance of oil. This causes no harm to your baby.