Seborrheic dermatitis is a common skin disorder that can be easily
treated. This condition is a red, scaly, itchy rash most commonly
seen on the scalp, sides of the nose, eyebrows, eyelids, skin behind
the ears, and middle of the chest. Other areas, such as the navel
(belly button), buttocks, skin folds under the arms, axillary regions,
breasts, and groin, may also be involved.
Seborrheic dermatitis most often occurs in babies younger than 3 months
of age and in adults from 30 to 60 years of age. In adults, it's more
common in men than in women.
The exact cause isn't known. The cause may be different in
infants and adults. Seborrheic dermatitis may be related to
hormones, because the disorder often appears in infancy and
disappears before puberty. Or the cause might be a fungus, called
Pityrosporum ovale. This organism is normally present on the
skin in small numbers, but sometimes its numbers increase, resulting
in skin problems.
Seborrheic dermatitis has also been linked to neurologic disorders
such as Parkinson's disease and epilepsy. The reason for this relationship