Cradle cap or cradle hat causes crusty or oily scaly patches on a baby's scalp. The condition is not painful or itchy, but it can cause thick white or yellow scales that are not easy to remove. Cradle cap most commonly begins sometime in the first three months but can occur in later years. Similar symptoms in older children are more likely to be dandruff than cradle cap. The rash is often prominent around the ear, the eyebrows or the eyelids. It may appear in other locations as well, where it is called infantile seborrhoeic dermatitis. Cradle cap is just a special—and more benign—case of this condition. The exact cause of cradle cap is not known. Cradle cap is not spread from person to person (contagious). It is also not caused by poor hygiene. It is not an allergy, and it is not dangerous. Cradle cap often lasts a few months. In some children, the condition can last until age 2 or 3.
Cradle cap is seborrheic dermatitis that affects infants. It presents on the scalp as greasy patches of scaling, which appear thick, crusty, yellow, white or brown. The affected regions are not usually itchy and do not bother the child. Other affected areas can include the eyelids, ear, around the nose, and in the groin. Hair loss can also occur.
Cradle cap is not caused by bacterial infection, allergy or poor hygiene. Cradle cap is also not contagious. Doctors do not agree on what causes cradle cap, but the two most common hypotheses are fungal infection and overactive sebaceous glands. Cradle cap is an inflammatory condition.
Possibly it has to do with overactive sebaceous glands in the skin of newborn babies, due to the mother's hormones still in the baby's circulation. The glands release a greasy substance that makes old skin cells attach to the scalp instead of falling off as they dry. There is a relationship with skin yeasts (Pityrosporum ovale, newly renamed Malassezia furfur).
If the condition thickens, turns red and irritated, starts spreading, appears on other body parts, or if the baby develops thrush (fungal mouth infection), fungal ear infection (an ear infection that does not respond to antibiotics) or a persistent diaper rash, medical intervention is recommended.