Flaky scalp after dying hair

Hair dye can trigger irritant or allergic contact dermatitis. Itching, burning, redness, tightness, or scale starting after colouring makes a product reaction possible, especially if dye touched the scalp. Swelling around the ears, eyelids, or face is more concerning for allergy. Flakes can also occur with Dandruff or Seborrheic Dermatitis, and dye may make an existing problem more noticeable. Thick, sharply defined plaques suggest Scalp Psoriasis. Scalp Ringworm may cause scale with broken hairs or patchy hair loss and requires a medical diagnosis.

Stop using the suspected dye and do not recolour until the scalp has recovered and a clinician has advised you. Rinse thoroughly with lukewarm water if residue remains, then use a gentle, fragrance-free shampoo. Avoid scratching, exfoliating scalp brushes, bleach, and home mixtures. Keep the dye box or ingredient list for the appointment, and record the timing of application and symptoms. If there is no burning or swelling but ordinary flakes continue, ask whether Medicated Shampoo Treatment is appropriate rather than choosing a product at random.

Contact a clinician promptly for spreading redness, marked tenderness, blisters, wet discharge, facial or eyelid swelling, or patchy hair loss. Emergency help is needed for breathing difficulty, throat tightness, faintness, or rapidly developing swelling after dye. Arrange a dermatology appointment when flaking persists or recurs, because identifying the responsible ingredient can help prevent another reaction.

Ask whether this looks like contact dermatitis or Dandruff, whether patch testing may help identify an ingredient, and which hair-washing and treatment options are safe while the scalp is inflamed.