Cradle cap is a very common condition of the scalp skin in young infants. It usually appears in the first two months of life in the form of yellowish-white greasy scales or crusts over the scalp. It looks alarming, but is nonetheless a benign and self-limited condition.
What causes cradle cap?
Cradle cap is the infant version of dandruff. In other words, it is a form of skin inflammation in reaction to certain components of sebum.
The skin covering most parts of our body bears hair follicles, more or less in number according to our genetic predisposition. These hair follicles have sebaceous glands attached to them. They secrete a fatty substance called sebum which lubricates the hair and makes the skin waterproof.
The production and release of sebum are exaggerated in some babies because of the high levels of sebum-stimulating hormones in their blood, passed from the mother during pregnancy. For this reason cradle cap is medically termed seborrheic dermatitis.
In contrast to popular thinking, cradle cap is not caused by an allergy or infection. Its appearance, notwithstanding, is not due to low standards of hygiene in baby care either. The best-cared for baby may develop a bad case of cradle cap if the sebum glands are overactive.
It is important to note that, since the condition is not caused by infection, it is not contagious - thus babies with and without cradle cap may be with each other freely without fear of spreading the condition. The scales and crusts are composed of dead skin cells stuck together by the sebum and other skin oils.
Cradle cap is characterized by the appearance of large, yellowish or brownish greasy scales or crusts on the skin of the scalp. These are produced by inflammation, and the aforementioned crusts are thick and peeling. The underlying skin may appear red when the scales peel off. The hair may be stuck to the scales and may come off readily along with the crusted skin. However, the hair readily grows back again.
Uncomplicated cradle cap is never itchy, so if the baby keeps scratching the area, another diagnosis should be suspected. In the same way, cradle cap is not painful. Blisters, weeping lesions or eczematous rashes, as well as red, swollen skin or pustules are not part of this condition. The occurrence of any of these should prompt a medical consultation for appropriate diagnostic procedures and treatment.
Cradle cap most often occurs on the scalp, but may also be found less commonly on the neck, ears, face or body in the diaper area. The skin folds of the axilla or the back of the knee may also be affected. Infants who have cradle cap are more likely to have dandruff as they grow older.
Reviewed by: Dr Tomislav Meštrović, MD, PhD