What does seborrheic dermatitis look like?

The color depends on your skin tone

Flakes can be white to yellow. Some patches have thicker scales, but facial patches are often thin, with edges that are not sharply defined. The middle of the face can be oily in some places and dry in others. Around the hairline or on the chest, flaky patches can form rings or petal shapes.23

Where does it usually appear?

Look for the pattern as well as the flakes. Common sites include the scalp, eyebrows and the skin between them, sides of the nose, beard area, behind the ears and chest. More extensive seborrheic dermatitis can reach the armpits, belly button, groin or skin beneath the breasts.13

On the eyelids, seborrheic dermatitis can cause swelling, scaling and yellowish scale between the eyelashes. Around or inside the ears, it can cause crusting, cracks or oozing. Itching is often mild but can be intense on the scalp; burning can also occur.1

Is it dandruff or something else?

Dandruff is an uninflamed form of seborrheic dermatitis on the scalp: scattered flakes without an underlying inflamed rash. It can cause mild itching. Seborrheic dermatitis with inflammation adds visible patches and discoloration, and can involve the face or body rather than just the scalp.3

Appearance alone cannot reliably separate seborrheic dermatitis from psoriasis, contact dermatitis or a fungal infection. A dermatologist usually diagnoses it by examining the skin and asking about symptoms and medical history. Seborrheic dermatitis and psoriasis can also occur together, called sebopsoriasis. A biopsy, which examines a small skin sample, is sometimes needed when the diagnosis is unclear.34

What does it look like in babies?

In babies, seborrheic dermatitis is called cradle cap. It commonly causes greasy scalp scaling that can build into thick, yellow crusts. It can also spread into skin folds or the diaper area. On darker skin, lighter patches and flaking can be more noticeable than the classic yellow crust. Cradle cap is usually not especially itchy and generally clears within weeks to months.23

What should you do next?

For mild adult scalp dandruff, try a dandruff shampoo containing ketoconazole, coal tar or salicylic acid. A pharmacist can explain how to use a dandruff shampoo, which is more useful than a bottle with a motivational slogan. Follow the product directions and allow up to four weeks to assess improvement. For a suspected facial or body rash, arrange an examination rather than treating every flaky patch as dandruff.25

Adult seborrheic dermatitis often comes and goes, so maintenance treatment is sometimes necessary. Treatment aims to reduce flakes and itching, rather than give your bathroom shelf a promotion. Seborrheic dermatitis is not contagious.2

See a doctor if your scalp is very itchy, red or swollen, or dandruff persists after four weeks of shampoo treatment. Pain, swelling or draining fluid also need medical attention because they can signal infection. Seek help sooner if symptoms worsen or interfere with daily life.25