What are the signs of an allergic reaction to hair dye?

The signs of an allergic reaction to hair dye typically manifest as redness, itching, swelling, or a burning sensation on the scalp. These symptoms occur because the body identifies certain chemicals in the hair dye as harmful, triggering an immune response. This response often results in localized inflammation and discomfort, which are common characteristics of allergic reactions.

Options that refer to increased hair growth, changes in hair color or texture, and dryness and brittleness of hair are not associated with allergic reactions. Increased hair growth is not linked to dye application but rather relates to hormonal factors or other treatments. Changes in hair color or texture may occur due to the chemical processing of the hair but do not signify an allergic response. Similarly, dryness and brittleness are typically results of chemical damage or over-processing rather than an allergic reaction. Therefore, observing symptoms such as redness, itching, swelling, or burning sensation indicates a potential allergic response to the hair dye being used.