What to know about severe dandruff and an itchy scalp

Dandruff can cause loose flakes and itching without damaging the hair itself. Scratching can break the skin, increase irritation, and make it harder to tell simple flaking from another scalp disorder.

Seborrheic dermatitis commonly presents with itch and greasy or powdery scale, sometimes extending around the ears, eyebrows, or sides of the nose. Scalp psoriasis can present with thicker, more sharply defined scale that may extend beyond the hairline.

Folliculitis can present with itchy or tender bumps centred on hair follicles rather than flakes alone. Head lice commonly cause scalp itching, especially around the ears and back of the neck, with firmly attached eggs on hair shafts. Irritant or allergic reactions may begin after a new dye, oil, fragrance, shampoo, or styling product.

Use an anti-dandruff or medicated shampoo as directed on its label, applying it to the scalp rather than only the hair. Give the product the stated contact time before rinsing, and stop if it causes marked burning, swelling, or a spreading rash.

Keep fingernails short and use cool compresses instead of scratching. Pause newly introduced scalp products if irritation followed their use. Check for attached nits or moving lice before choosing lice treatment, because dandruff flakes usually brush away while nits adhere to individual hairs.

Arrange a medical review when symptoms persist despite correctly used medicated shampoo, repeatedly return, disturb sleep, or involve thick plaques, painful bumps, crusting, drainage, patchy hair loss, or broken hairs. These findings can change both the diagnosis and the appropriate treatment.

Seek prompt care for rapidly spreading redness, significant swelling, fever, severe tenderness, or pus, particularly when you feel unwell. Facial swelling, breathing difficulty, or throat tightness after a hair or scalp product requires emergency help.

Tell the clinician where the itch started, whether the scale is dry or greasy, which body areas are also affected, and which products you have tried. Ask whether the pattern fits dandruff, psoriasis, folliculitis, lice, or contact dermatitis; how each prescribed product should be applied; and which signs mean you should return sooner.