Sitting in a salon without proper ventilation may have caused your light-headedness. If you plan to keep coloring your hair, try visiting the salon early in the morning before high concentrations of chemicals build up, or use dye at home where you can open a window or go outside. Your itching scalp could also be caused by a true allergy, where the immune system identifies a substance as foreign and produces antibodies to fight it. Some types of allergies can affect breathing or digestion. Skin allergies, however, tend to be less serious because they affect only the area where the skin and the substance come into contact.
Most skin reactions are minor and disappear after a day or so.
But if your itching persists or any rashes continue to spread after 24 hours, see a doctor for further treatment. To prevent future reactions, find out what products your hair stylist used. Be sure to get a list of the ingredients and, if possible, a sample of the mixture. When the time is up, the doctor removes the bandage and looks for changes such as itching, rashes, or blotchy skin. The choice to continue using hair dye depends on the severity of your case and whether you can find products that are non-irritating.