Dandruff and Scalp Flaking: What Is Causing Your Flakes?

What causes flakes on the scalp

Dandruff vs dry scalp

This is the most common mix-up. In dandruff, the scalp is often oily and the flakes are larger and slightly yellow because of the oil. Washing more often helps. In a dry scalp, the flakes are small and white, the scalp feels tight, and washing too often with harsh shampoo makes it worse. Dry scalp improves with a gentler shampoo, fewer hot washes and a light conditioner or oil.

Dandruff vs scalp psoriasis

Psoriasis produces thick, raised, red plaques with silvery scale that is firmly stuck on. Plaques often spill over the hairline onto the forehead, neck or behind the ears. Look for psoriasis elsewhere: elbows, knees, lower back and pitted nails. Psoriasis usually needs prescription treatment.

Why dandruff happens

A yeast called Malassezia lives on everyone's scalp and feeds on scalp oil. In people prone to dandruff, its byproducts irritate the skin, which turns over faster and sheds in visible clumps. Dandruff is more likely:

• after puberty, when oil production rises, peaking in young adults
• in men
• in cold, dry weather
• with stress or poor sleep
• in people with Parkinson's disease, HIV or other conditions linked to seborrheic dermatitis

Poor hygiene does not cause dandruff, but infrequent washing lets flakes build up and become more noticeable.

Flaking in babies and children

• Cradle cap: greasy yellow crusts on a baby's scalp in the first months. Harmless; gently loosen with baby oil and a soft brush. See cradle cap.
• Tinea capitis (scalp ringworm): the most common cause of scaly scalp patches with hair loss in school-age children. Shampoo alone will not cure it. It needs oral antifungal medicine.
• True dandruff is uncommon before puberty, so persistent flaking in a child should be checked.

What helps

1. Use an anti-dandruff shampoo 2 to 3 times a week. Leave it on for 5 minutes before rinsing. Options include ketoconazole, zinc pyrithione, selenium sulfide, salicylic acid and coal tar.
2. Rotate between two different active ingredients if one stops working.
3. Once controlled, use it once a week to keep flakes away.
4. For dry scalp, switch to a gentle shampoo, wash in warm rather than hot water, and use a fragrance-free conditioner.
5. Stop any new hair product that coincided with the flaking.

See the dandruff condition page for a detailed comparison of shampoo ingredients and prescription options.

When to see a doctor

See a primary care doctor or dermatologist if flaking persists after a month of regular medicated shampoo, if the scalp is very red, sore or weeping, if you lose hair, or if you suspect psoriasis or ringworm. Diagnosis is usually made by looking. A skin scraping or hair sample may be tested for fungus.

Frequently asked questions

How do I know if it is dandruff or dry scalp?

Dandruff flakes tend to be larger, slightly yellow and oily, and the scalp may look greasy. Dry scalp flakes are smaller and white, and the scalp feels tight. Dandruff improves with medicated shampoo; dry scalp improves with gentler washing and moisturizing.

Is dandruff contagious?

No. Dandruff is caused by your own skin reacting to yeast that lives on everyone. You cannot catch it from sharing a hat or brush. Scalp ringworm, which can look similar in children, is contagious and needs antifungal tablets.

Can stress cause dandruff?

Stress does not cause dandruff directly, but it can trigger flare-ups in people who are prone to it, likely through effects on the immune system and oil production. Poor sleep and cold, dry weather are other common triggers.

Why do I still have dandruff after washing my hair?

Washing removes flakes but not the underlying cause. Ordinary shampoo does not control the yeast involved. Use a medicated anti-dandruff shampoo, leave it on for a few minutes, and use it regularly. If that fails after a month, see a doctor.

Can dandruff cause hair loss?

Dandruff itself does not usually cause hair loss, though heavy scratching can break hairs. Flaking with patchy hair loss suggests another cause, such as scalp ringworm, psoriasis or a scarring condition, and should be checked.