What is one common symptom of an allergic reaction to hair dye?

One common symptom of an allergic reaction to hair dye is itching and redness. This occurs because hair dye often contains various chemicals, including paraphenylenediamine (PPD), which can act as allergens for some individuals. When someone is allergic to these substances, their immune system mistakenly identifies the ingredients as harmful, triggering an inflammatory response. This response manifests as itching and redness in the scalp or areas where the dye has been applied, as the body releases histamines and other substances to combat what it perceives as a threat.

The other options do not relate to allergic reactions. Increased hair growth and improved hair texture are not consequences of an allergic response. Similarly, faster drying time does not pertain to any typical allergic reaction symptoms and instead reflects characteristics of the dye products used. Understanding these reactions is crucial for cosmetologists to ensure safety and provide appropriate alternatives for clients with known sensitivities.