What Is Seborrheic Dermatitis?
Seborrheic dermatitis is a common skin disease that causes an itchy rash with flaky scales. It causes redness on light skin and light patches on darker skin. It’s also called dandruff, cradle cap, seborrhea, seborrheic eczema, and seborrheic psoriasis.
It might look similar to psoriasis, eczema, or an allergic reaction. It usually happens on your scalp, but you can get it anywhere on your body.
Seborrheic Dermatitis Causes
Experts don’t know what exactly causes seborrheic dermatitis. It seems to be a mix of things, including:
- Your genes
- A yeast that usually lives on your skin without causing problems
- Certain medical conditions and medicines
- Cold, dry weather
- An immune system response
It doesn’t come from an allergy or from being unclean.
Seborrheic Dermatitis Risk Factors
Newborns and adults ages 30 to 60 are more likely to get seborrheic dermatitis. It’s more common in men than women and in people with oily skin. These conditions can also raise adults’ risk:
- Eating disorders
- Heart attack or stroke recovery
- Parkinson’s disease
Seborrheic Dermatitis Symptoms
Babies 3 months and younger often get cradle cap: crusty yellow or brown scales on their scalp. It usually goes away before they’re a year old, although it can come back when they reach puberty.
Parents might mistake seborrheic dermatitis for diaper rash.
Adults might get seborrheic dermatitis on their face, especially around their nose, in their eyebrows, on their eyelids, or behind their ears. It can show up on other parts of your body, too:
- In the middle part of your chest
- Around your navel
- On your buttocks
- In skin folds under your arms and on your legs
- In your groin
- Below your breasts
Your skin might itch or burn. The scales that flake off could be white or yellowish and look moist or oily.
Because seborrheic dermatitis can look like other skin conditions, see your doctor to get a diagnosis and a treatment plan.
Seborrheic Dermatitis Diagnosis
Your doctor will ask about your medical history and look at your skin. They might scrape off a bit of skin and look at it under a microscope to rule out conditions that affect your skin including:
- Psoriasis. This causes a lot of silvery white scales, often on your elbows and knees. It can also change how your fingernails look. You might have this at the same time as seborrheic dermatitis.
- Eczema (atopic dermatitis). This usually causes inflamed skin on your head, elbows, or knees.
- Rosacea. This can also happen along with dermatitis. It causes a red rash with few or no scales, often on your face. Rosacea can go away and come back several times.
- Allergic reaction. If your rash is itchy and doesn’t clear up with treatment, an allergy could be causing it.
- Systemic lupus erythematous (SLE). Some stages of this condition can cause a butterfly-shaped rash across the middle of your face.
Seborrheic Dermatitis Treatment
Seborrheic dermatitis will sometimes clear up by itself. But often, it’s a lifelong issue that clears and flares. You can usually control it with good skin care.
Talk with your doctor about a treatment plan. They’ll probably tell you to start with over-the-counter medicines and home remedies.
If you have seborrheic dermatitis on your scalp, use an over-the-counter dandruff shampoo with one of these ingredients:
- Coal tar
- Salicylic acid
- Selenium sulfide
- Zinc pyrithione
If your baby has cradle cap, shampoo their scalp daily with warm water and baby shampoo. A dandruff shampoo could irritate their skin, so talk to your pediatrician about medicated shampoos before you try one. To soften thick patches, rub mineral oil onto the area and brush gently with a baby hairbrush to help peel the scales off.
If you have seborrheic dermatitis on your face and body, keep the affected areas clean. Wash with soap and water every day.
Sunlight may stop the growth of the yeast organisms that are causing the problem, so being outdoors could help make the rash go away. Make sure to wear sunscreen.
Other treatments include:
- Antifungal products
- Corticosteroid lotions
- Sulfur products
These medicines can have side effects, especially if you use them for a long time. Follow your doctor’s advice. The best results often come from a mix of treatments.
See your doctor if your seborrheic dermatitis doesn’t get better, if the area becomes painful, red, or swollen, or if it starts to drain pus. They might give you prescription cream, shampoo, or antifungal pills to clear up the symptoms.