This is a very common skin disease that causes a rash. When this rash appears, it often looks like the one pictured above. The skin tends to have a:
- Reddish color.
- Swollen and greasy appearance.
- White or yellowish crusty scale on the surface.
One or more of these rashes can appear on the body. Sometimes, the affected skin itches.
Cradle cap: A type of seborrheic dermatitis
Many infants get cradle cap. This is a type of seborrheic dermatitis (seb-uh-ree-ick dur-muh-tahy-tis) that develops in babies. Scaly, greasy patches form on the baby’s scalp. The patches can become thick and crusty, but cradle cap is harmless. Cradle cap usually goes away on its own within a few months.
Babies also get seborrheic dermatitis in their diaper area and elsewhere. In the diaper area, the red rash often is mistaken for diaper rash. A few babies get seborrheic dermatitis that covers much of the body with red, scaly patches.
No matter where the seborrheic dermatitis forms, it tends to permanently disappear between 6 months and 1 year of age.
Seborrheic dermatitis is long-lasting in adults
When an adult gets seborrheic dermatitis, the condition can come and go for the rest of the person’s life. Flare-ups are common when the weather turns cold and dry. Stress also can trigger a flare-up. The good news is that treatment can reduce flare-ups and bring relief.
Adults and adolescents
Seborrheic dermatitis causes:
- Scaly patches on the skin.
- The skin beneath these patches is reddish.
- Although scaly, patches often look greasy or moist.
- Scales can flake off and tend to be yellowish to white.
In adults and adolescents, the skin can:
- Itch, especially on the scalp and in the ear canal.
Patches form where the skin is oily:
- Ears (around and in the ear canal).
- Eyebrows (the skin beneath).
- Center of the face.
- Upper chest.
- Upper back.
Patches form where the skin is oily, such as on the scalp, face, and in the ear canals.
When an infant gets seborrheic dermatitis, it tends to form on the scalp and is known as cradle cap. Signs and symptoms of cradle cap include:
- Yellow, greasy scale on the scalp.
- A thick layer of scale can cover the entire scalp.
- Scale is often yellow to brownish in color.
- With time, the scale becomes flaky and easily rubs off.
In infants, seborrheic dermatitis also can form on the face, usually on a baby’s eyelids, around the nose, or ears. It also forms in the diaper area. In a few babies, seborrheic dermatitis covers most of the body.
Most infants seem unbothered by seborrheic dermatitis. Cradle cap sometimes itches.
What causes seborrheic dermatitis?
Researchers are still studying what causes this common skin disease. From what they have learned, it appears that the cause is complex. Many factors seem to work together to cause seborrheic dermatitis. These factors may include the yeast that normally lives on our skin, our genes, living in a cold and dry climate, stress, and a person’s overall health.
By studying seborrheic dermatitis, researchers have learned the following:
- It is not caused by poor personal hygiene.
- It is not an allergy.
- It does not harm the body.
Who gets seborrheic dermatitis?
People of all colors and ages get seborrheic dermatitis. You have a higher risk if any of the following apply to you.
People in these two age groups are most susceptible:
- Infants 3 months of age and younger.
- Adults between 30 and 60 years of age.
Your risk increases if you have any of these medical conditions:
- HIV (About 85 percent of people infected with HIV develop seborrheic dermatitis).
- Acne, rosacea, or psoriasis.
- Parkinson’s disease.
- Stroke or heart attack (recovering from).
- Eating disorder.
If you are taking any of the following medicines, your risk for seborrheic dermatitis increases:
Infants (scalp): Called cradle cap, this tends to completely disappear without treatment. If treatment is necessary, a dermatologist may recommend:
- Shampooing the baby’s scalp daily with a baby shampoo.
- Gently brushing away the scale, once scale starts to soften.
- Applying a medication to the infant’s scalp.
Infants (skin beyond the scalp): This, too, will clear. If treatment is needed, a dermatologist may prescribe a medicine that can be applied to the child’s skin.
Adolescents and adults (scalp and rest of body): After infancy, seborrheic dermatitis usually does not go away without treatment. For the best results, a dermatologist will consider many factors before creating a treatment plan. Treatment may include:
- Dandruff shampoos.
- Medicine to apply to the skin for short periods of time.
- Barrier-repair cream.
Infant: Seborrheic dermatitis often completely disappears by 6 months to 1 year of age. It can return when the child reaches puberty.
Adolescent or adult: A few people see seborrheic dermatitis clear without treatment. More often, seborrheic dermatitis lasts for years. It tends to clear and flare without warning. Treatment often is necessary to control it.