How long does it take to recover from dandruff after hair coloring is mainly determined by the cause of dandruff, and different causes correspond to different recovery times. Dandruff after hair coloring is commonly associated with seborrheic dermatitis, fungal infections, and allergic dermatitis; 1. Allergic dermatitis: large dandruff after hair dyeing is related to scalp allergy to hair dyes and other chemicals, which stimulates the scalp to produce itching, redness, pimples, increased dandruff, etc. It requires the use of anti-allergic drugs, such as topical glycerine lotion, oral levocetirizine and other treatments, which can be cured in about three days in general. 2. Fungal infections: due to hair dyeing utensils, barber tools, etc. are not disinfected, not disposable, in the process of dyeing the hair may be infected with fungi, resulting in dandruff after dyeing the hair, you can use clotrimazole cream, ketoconazole cream, such as topical rub, oral fluconazole capsules, etc.. Scalp fungal infection is more stubborn, usually takes months to recover, and also has the possibility of recurrence. 3. Seborrheic dermatitis of the scalp: If you have seborrheic dermatitis of the scalp before dyeing your hair, which leads to increased dandruff, erythema of the scalp, greasiness, etc., you can use minoxidil tincture topical rubbing, oral tanshinone capsules, etc.. The recovery time is relatively long, usually about two weeks, and there is a possibility of recurrent episodes, the recovery time is even longer. After dyeing hair with large dandruff, it is recommended to go to the hospital in a timely manner, to clarify the cause of the cause of treatment, do not blindly use their own medication.