Symptoms of scalp allergy include itching, rash (including erythema, papules, pimples, blisters) and so on. 1. Itching: when the scalp comes into contact with allergens, it will cause the body to produce antibodies, which will release histamine, causing the patient’s skin to itch. 2. Rash: scalp contact with allergens will cause a series of allergic reactions, the main symptoms of various types of rashes, such as erythema, papules, papules, blisters and other manifestations, if the rash area is extensive, it is easy to secondary bacterial infections may occur in the scalp area of the diffuse swelling, vesicles, yellow oozing, crusting and other symptoms. Scalp allergy should first clarify the allergens, such as shampoo, conditioner, hair dye, etc., the symptoms are mild, when away from the allergens, the symptoms will gradually ease, if the condition is serious, it is recommended to go to the hospital in time for treatment.