Answer: The actual cause of seborrhea dermatitis is still unclear. However, scientists believe that several things could cause it:
The first cause is the excessive production of oil on the skin. When the oil becomes in excess, it irritates the skin, causing greasy and reddish appearances.
The second suspected factor is a type of yeast known as Malassezia, which exists naturally on the skin's oil. When it multiplies in excess, that may trigger an inflammatory response from the skin.
Another cause is hormonal changes which may occur during pregnancy.