It is a type of dermatitis called seborrheic dermatitis which occurs in areas rich in sebaceous glands, like the face, scald and diaper (nappy) region.
It is common in infants, usually appearing between 2 and 10 weeks of age. It usually resolves by 1 year. It does not generally occur in children older than 1 year of age.
What does cradle cap look look like?
It is a greasy layer of scales that are yellow-pinkish in color that cover the baby's scalp or part of it. The picture on the right is characteristic.
What is the treatment of cradle cap?
Seborrheic dermatitis on the scalp doesn't usually cause any distress so many parents don't do anything about it. It will clear with time.
If you want to remove it,
the scaly layer needs to be softened so it gently comes off with gentle wiping.
Do not scrape the scales off. You can soften the scales by applying olive oil (the carrier oil you get from a pharmacy not the cooking oil). Apply and leave for 15 mins and then gently wash your baby's hair with shampoo and then gently dry the head wiping the scales away gently.
Occasionally a shampoo containing sulphur and salicylic acid (such as Sebulex or Egozite Cradle Cap) will be required.
What does seborrheic dermatitis in other areas look like?
Seborrheic dermatitis causes scales that can crust and often have a greasy yellowish appearance on a red background. It is not as itchy as eczema.
The picture on the right shows the waxy, slightly yellow scaling seen in seborrheic dermatitis on a baby's face.

What is the treatment for seborrheic dermatitis in the diaper (nappy) area or face?
1% hydrocortisone cream can be used daily for seborrheic dermatitis in the diaper (nappy) area or for seborrheic dermatitis on the face. Sometimes, when the diaper (nappy) area is affected, treatment for thrush with an antifungal agent is also necessary.