What a badly flaky scalp may be telling you

The appearance and distribution give useful clues. Loose white or yellowish flakes with an oily scalp fit a different pattern from sharply bordered thick plaques or a scaly patch with broken hairs. Scratching can create small wounds and make irritation worse.

Dandruff and seborrheic dermatitis commonly present with scalp flaking; seborrheic dermatitis can also cause greasy scale and redness around the hairline, ears or eyebrows. Scalp psoriasis often produces thicker, more defined areas of scale that may extend beyond the hairline.

Scalp ringworm can present with scale plus broken hairs, tender areas or patchy hair loss. It needs clinician-directed treatment and can spread between people. Product irritation is another possibility when burning or a rash follows hair dye, oil, fragrance or a new styling product.

Wash with lukewarm water and massage with fingertips instead of nails. Pause newly introduced fragranced or harsh products. A medicated anti-dandruff shampoo may help a dandruff-type pattern; follow its label because the required scalp contact and frequency vary by ingredient.

Rinse thoroughly and avoid sharing combs, towels, hats or pillowcases if there are broken hairs or suspicious patches. Do not scrape adherent scale. Note whether flakes involve the ears, eyebrows, neck or other body areas, as that distribution can help a clinician distinguish causes.

Book medical care for patchy hair loss, broken hairs, pus, crusting, painful swelling, open sores or flaking that persists despite appropriate shampoo use. Seek prompt assessment if redness spreads quickly, fever develops, the face swells, or the scalp becomes very painful. A child with a scaly hair-loss patch should be checked rather than treated as routine dandruff.

Ask whether the pattern looks fungal, inflammatory or related to contact with a product; whether testing is useful; and exactly how a prescribed shampoo or scalp medicine should be applied. Bring a list of recent hair treatments and any products already tried.