Kentucky Cosmetology State Practice Exam 2026 - Free Cosmetology Practice Questions and Study Guide

A common allergic reaction to hair color is characterized by itching and redness. This reaction often occurs due to ingredients such as paraphenylenediamine (PPD), which can trigger sensitive skin responses in some individuals. When someone with a sensitivity to these chemicals is exposed, the immune system may overreact, leading to localized symptoms such as itching, redness, and inflammation on the scalp or surrounding skin. This response is a form of contact dermatitis, which can be uncomfortable and may require treatment.

Other symptoms associated with hair products might involve dryness and flaking, but these are generally not indicative of an allergic reaction. Pain and swelling can suggest a more severe condition or chemical burn rather than a typical allergic response. Patchy hair loss is usually related to other factors, such as stress or underlying health conditions, rather than a direct reaction to hair color itself. Understanding these reactions helps practitioners and clients make informed choices about hair coloring and sensitivity testing before application.