Congratulations on your beautiful baby! Now what in the world are these flakes on her eyebrows, the yellow or brown crust scale on his scalp and the weepy red rash under the neck and armpits? Cradle cap on babies starts as early as 3-4 weeks after birth. Some other ways this condition may be referred to as is: seborrheic dermatitis (the official medical term), crusta lacteal, milk crust, pityriasis capitis, or in Spanish “costra lactea.” All of these are synonyms for the same thing. Despite cradle cap on babies looking unpleasant, it usually does not bother the baby. Sometimes people will say there is dandruff on the baby’s head, or think that this may be related to poor hygiene. What causes Cradle Cap on babies? The crust color of cradle cap depends on the pigmentation of your baby’s skin. The crust can be white, or yellow or brown. The medical community believes that this cradle cap on babies comes from naturally occurring yeasts/fungus (of the species Malassezia) on the skin that eat an oily substance called “sebum.” Sebum is produced by “sebaceous glands” and its role is to protect and lubricate the skin. The metabolism of this oily substance by the Malassezia makes an irritating byproduct that irritates the skin and causes excess flaking. The natural skin barrier is thus disrupted and then the skin becomes more permeable allowing for more irritation. Almost everyone (from newborns to adults), has this yeast on the scalp and body, but not every baby has cradle cap. It is thought that maternal hormones and the immune system also has a role in development of cradle cap. Can cradle cap on babies be prevented? As mentioned earlier the Cradle Cap on your baby is not caused by anything within your control, it is not easily prevented. But you can use certain products to gently care for your baby’s skin, soften the scales of cradle cap on the scalp, and possibly prevent future flaking and scaling from developing. A gentle medicated baby shampoo for Cradle Cap containing Pyrithione Zinc is an excellent way to quickly remedy cradle cap.