You know there really isn't as they are both due to seborrheic dermatitis, an inflammatory condition of the skin in which the skin overproduces skin cells and sebum (the skins natural oil). Cradle cap is the term used for the scaly dermatitis seen on the scalp in infants. It is also seen on the eyelids, eyebrows, and behind the ears. It is typically seen after about three months of age and will often resolve on its own by the time a baby is eight to 12 months old. It is usually simply a cosmetic problem for a baby as it looks like a yellowish plaque on a baby's scalp and is often not even noticed by anyone other than the parents. Unlike seborrheic dermatitis in adults, cradle cap typically doesn't itch. It is thought that cradle cap may occur in infancy due to hormonal influences from the mother that were passed across the placenta to the baby. These hormones cause the sebaceous glands to become over active. In some severe cases an infant's scalp becomes really scaly and inflamed and causes even more parental concern, as it appears that the infant is uncomfortable and may be trying to scratch their head by rubbing it on surfaces. The treatment for cradle cap is to wash the baby's scalp daily with a mild shampoo and then to use a soft comb or brush to help remove the scales once they have been loosened with washing. When washing the head make sure to get the shampoo behind the ears and in the brows (keeping the soap out of baby's eyes). This is usually sufficient treatment for most cradle cap. In situations where the greasy scales seem to be worsening it may help to put a small amount of mineral oil or olive oil on the baby's head and let it sit (I left a small amount on my children's heads overnight) and then to shampoo the following day. The oil will help the scales to loosen up and come off more easily. For babies that have very inflamed irritated cradle cap a visit to your pediatrician may be warranted to confirm the diagnosis. In persistent cases I often recommend shampooing several times a week with a dandruff shampoo that has either selenium (Selsun) or zinc pyrithione (Head and Shoulders) making sure not to get any in the infant's eyes. I may then also use a hydrocortisone cream or foam on the scalp that will lessen the inflammation and itching. In these cases it may take several weeks to totally clear up the problem. As children get older, especially during puberty, you may see a return of seborrhea as dandruff. Again you can use dandruff shampoos. It also seems that with the overproduction of sebum there is an overgrowth of a fungus called malessizia so  using a shampoo for dandruff as well as a antifungal shampoo (Nizoral) often works. I have teens alternate different shampoos, as sometimes it seems to work better than always using the same shampoo for months on end. Teens don't like white flakes falling from their scalp and unlike a baby, a teen is worried about the cosmetic issues of seborrhea! That's your daily dose, we'll chat again tomorrow. Send your question to Dr. Sue!