Dry hair and dandruff may be caused by contact dermatitis, or it may be a symptom of furuncle or ringworm of the scalp, which requires timely consultation to clarify the cause. 1. Contact dermatitis: associated with contact with irritating shampoos or hair dyes, perms, etc., can lead to skin irritation or allergic reactions, causing dry scalp, flaking, erythema, pimples and other reactions. 2. Scalp chaffing: the cause of scalp chaffing is not completely clear, and fungal infection, sebaceous gland metabolic abnormalities. Diffuse dry flaking of the scalp may occur. 3. Tinea capitis: It is caused by fungal infections such as Microsporum canis, Microsporum gypsum, etc. It is mainly transmitted through direct skin contact or indirectly by items such as hats and towels. Fungal infection of the scalp is prone to dandruff, itching sensation, accompanied by hair breakage. It is necessary to go to the hospital for consultation to clarify the cause of the disease.