What is seborrheic dermatitis?
Seborrheic dermatitis is a skin condition that causes white-to-yellow greasy scales to form on the scalp, ears, and face. If it occurs on the scalp in babies, it is called "cradle cap." If it appears on the scalp in adults, it is known as dandruff.
Seborrheic dermatitis can cause various areas of the skin to be flaky or itchy. It usually affects the scalp, but can also affect other parts of the body. Common sites include the sides of the nose, eyebrows, ears, eyelids, and chest. It can also occur in the navel (belly button) and in the creases of the arms, legs, or groin.
Who gets seborrheic dermatitis?
Seborrheic dermatitis occurs most often in infants younger than three months old and in adults between the ages of 30 and 60. It is more common in men than in women.
What are the symptoms of seborrheic dermatitis?
Seborrhea of the scalp causes dandruff, which appears as loose, white flakes of skin that may itch. Seborrhea on other areas of the body can produce patches of skin that are red and scaly.
Cradle cap in infants appears as crusty yellow or brown scales on the scalp. This scaling can also be found on the eyelids, around the nose, and in the groin, and may itch. Scratching may cause additional inflammation in the area and may cause breaks in the skin, which can lead to mild infections or bleeding.
What are the causes of seborrheic dermatitis?
Seborrheic dermatitis can have many different causes. Hormones may play a role. A yeast called Malassezia, which is normally present on the skin, may overgrow and cause skin problems.
Other factors that can cause seborrheic dermatitis include:
- Family history (other members of your family have it)
- Extremes in weather
- Oily skin
- Infrequent shampoos or skin cleaning
- Using alcohol-based lotions
- Other skin disorders
Certain conditions such as Parkinson's disease, epilepsy, human immunodeficiency virus (HIV) infection, stroke, and head injury can cause seborrheic dermatitis.