Whether you dye your own hair or go to a barber store, you may experience allergies, and even if you did not have allergies before, you may experience allergies when you dye your hair again, mainly in the form of red spots on the scalp or facial area, accompanied by significant itching, and in severe cases, local oozing, pus, water, or even significant swelling of the entire face and scalp. If there is a bacterial infection, fever and other symptoms may occur. Most patients can get good control or cure after 7-10 days of treatment.