Allergic hair dyeing, resulting in bumps and running water on the scalp, may be contact dermatitis. It is recommended to take good care of the affected area and give glucocorticoid, antihistamine and antibiotic drugs to help recovery. 1. Pay attention to the care of the affected area; there are more types of hair dyes, and if you are allergic to the ingredients inside the hair dyes, it may lead to bumps and running water on the scalp. It is recommended not to scratch the irritation and rinse out the residue of the hair dye to avoid further aggravation of the symptoms. 2. Glucocorticosteroids: In the acute stage of contact dermatitis, glucocorticosteroids can be given, such as prednisone and dexamethasone, which have anti-inflammatory and anti-allergic effects, and can quickly relieve the inflammatory reaction. 3. Antihistamine drugs: If the itching symptoms are more obvious, oral antihistamines can be given, such as cetirizine, loratadine, can reduce the release of histamine in the skin, to relieve local exudation. 4. Antibiotics: Allergies lead to itchy skin, scratching induced bacterial infection, can be applied with topical fusidic acid ointment, mupirocin ointment, can control the infection. Hair dye allergy leads to skin damage, such as swelling, pain, blisters, vesicles, oozing, it is recommended to go to the hospital dermatology department for examination in time, and give appropriate medication under the guidance of the doctor.