Seborrheic dermatitis: dandruff, face and cradle cap

Seborrheic dermatitis is a common inflammatory skin condition that makes white or yellowish scales on oily areas. Dandruff is its mildest form. When it affects a baby's scalp, it is called cradle cap.

The exact cause is not known. According to MedlinePlus, oil gland activity, a yeast that lives on the skin (Malassezia), skin barrier changes and genetics may play a role. It gets worse with stress, fatigue, weather extremes and alcohol, and it is more common in people with Parkinson disease or after a stroke. It is long-lasting: it comes and goes, but it can be controlled. It is not contagious and not caused by poor hygiene.

It is different from eczema (atopic dermatitis) and contact dermatitis; if that is what you have, see eczema and dermatitis.

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Seborrheic dermatitis is handled in a doctor visit, the same price for every age, with no membership. A refill of a treatment you already use is a follow-up visit. You pay by card when you request the visit, with a full refund if the clinic can’t see you. See all prices.

It appears on the scalp, eyebrows, eyelids, creases of the nose, lips, behind the ears, in the outer ear and on the middle of the chest. The most common symptoms are:

• White or yellowish scales (dandruff)
• Greasy, oily skin in those areas
• Itching
• Mild redness

What works best for dandruff is a dandruff shampoo with one of these ingredients: zinc pyrithione, salicylic acid, sulfur, selenium sulfide, ketoconazole or coal tar, according to the American Academy of Dermatology (AAD). Dandruff is the mildest form of seborrheic dermatitis, so dandruff treatment follows the same idea: control the flakes and the itch.

How to use it: for fine, straight or oily hair, the AAD suggests washing often and using the dandruff shampoo about twice a week; for coarse, curly or coily hair, about once a week if tolerated, applied only to the scalp so it does not dry out your hair. Some shampoos need 5 to 10 minutes on the scalp before rinsing; follow the label. If one does not work, alternate with a shampoo that has a different active ingredient. Coal tar can make the scalp more sensitive to the sun.

If your dandruff does not improve with these shampoos, or you have thick scales, redness or a strong itch, the doctor evaluates you by video. Flakes with bald patches, especially in children, can be scalp fungus, which needs different treatment. If appropriate, the doctor prescribes a stronger shampoo or cream and we send your prescription to your pharmacy.

On the scalp it looks like dandruff: white flakes, or yellowish, oily, sticky scales, with itching. On the face it shows up on the eyebrows, eyelids, the creases beside the nose, the lips and behind the ears, often with mild redness. Sometimes it forms plaques over a larger area.

On the face, the doctor tells you which gentle products to use and for how long, because the skin of the face and eyelids is thin. If your hair is also falling out in patches or in large amounts, it may have other causes: mention it to the doctor at your visit (see hair loss).

If the scales form thick, silvery plaques on the elbows, knees or scalp, it may be psoriasis; if the itching and dry skin are in the creases of the arms and legs, it may be atopic dermatitis. The doctor helps you tell them apart.

MedlinePlus lists over-the-counter shampoos and creams that help, with salicylic acid, coal tar, zinc, resorcinol, ketoconazole or selenium sulfide. Leave the shampoo on for a few minutes before rinsing, and follow the label.

For stronger cases, the doctor may prescribe a stronger antifungal shampoo or cream, or a short course of a corticosteroid cream. Because seborrheic dermatitis comes and goes, the plan usually includes what to use when it flares again.

See the doctor if it does not improve with home care, or if patches drain fluid or pus, form crusts, or become very red or painful.

Cradle cap is seborrheic dermatitis on a baby's scalp. It is not contagious, not an allergy, not dangerous and not caused by poor hygiene. It often lasts a few months, and in some children until age 2 or 3.

At home: massage the scalp with your fingers or a soft brush to loosen the scales, wash it daily with a mild shampoo, and brush the hair with a clean, soft brush. If the scales do not loosen, MedlinePlus suggests rubbing in mineral oil, covering with a warm cloth for up to an hour, then shampooing.

See the doctor if it does not improve with home care, spreads, drains or gets very red, or if your baby has a fever or seems ill. We see children of all ages; a parent or legal guardian is on camera with ID. See rash in children.

Seborrheic dermatitis is not an emergency. For your safety, get in-person care or call 911 if you notice:

• Very red, hot, swollen skin that is spreading, with fever
• A baby with fever, who will not feed or who seems very ill
• A baby under 3 months with a temperature of 100.4 °F (38 °C) or higher