What should you know about excessive flakes on scalp?

Small white or yellow flakes with itch are often linked with dandruff or seborrheic dermatitis. Thick, sharply defined scale extending beyond the hairline can occur with scalp psoriasis. Broken hairs, tender patches, swelling, or areas of hair loss raise concern for scalp ringworm, which needs medical treatment. New flaking can also follow a hair product, dye, or infrequent washing. Flaking alone cannot identify the cause, so redness, pain, location, and hair changes are useful clues.

Wash regularly with a gentle shampoo and avoid scratching, as broken skin can become irritated or infected. A medicated shampoo may help some causes; follow its label directions and allow it to contact the scalp for the recommended time. Stop a recently introduced product if burning or a rash started after use. Do not share combs, brushes, hats, or towels when an infection is possible. A clinician can examine the scalp and choose treatment for persistent or severe flaking.

Arrange an appointment for painful scale, bleeding, pus, thick plaques, spreading redness, or flaking that persists despite appropriate shampoo use. Seek prompt assessment for patchy hair loss, broken hairs, swollen lymph nodes, or a tender scalp, especially after close contact with someone who has a scalp infection. Urgent care is appropriate if you feel very unwell with a rapidly worsening scalp reaction.

What features distinguish dandruff, psoriasis, and infection in my scalp? Which shampoo should I use and for how long? Could a product or medicine be causing the flaking?