What causes itchy scalp?

Flaking that is white or greasy often occurs with dandruff or seborrheic dermatitis. Thick, sharply defined plaques that extend beyond the hairline can occur with scalp psoriasis. Small tender or pus-filled bumps around hairs may indicate folliculitis. Sudden itch with crawling insects or firmly attached nits raises concern for head lice. A new dye, shampoo, oil, or styling product can cause contact irritation, while frequent washing or hot water can dry the scalp.

The same person can have more than one contributor, so the pattern, timing, and appearance matter more than itch intensity by itself.

Use lukewarm water and a gentle, fragrance-free cleanser, and rinse hair products thoroughly. Avoid scratching, picking scale, or sharing combs, brushes, hats, and towels. If flaking persists, a clinician or pharmacist can help choose a medicated shampoo and explain how long to leave it on and how often to use it. Suspected lice need confirmation and a suitable head-lice treatment, with attention to close contacts and household items.

Arrange a review if the itch lasts, returns frequently, causes hair loss, or is accompanied by thick scale, bleeding, or painful bumps. Seek prompt care for spreading redness, swelling, pus, fever, severe pain, or sores that do not heal. A clinician can distinguish dandruff from psoriasis, infection, lice, or a reaction to a product.

Bring a list of recent hair products and describe flaking, bumps, hair loss, or household itching. Ask whether the scalp needs an examination, a medicated shampoo, treatment for lice, or a different plan for psoriasis or seborrheic dermatitis.