What is the most common adverse effect of hair coloring?

Allergic reactions are the most common adverse effect of hair coloring due to the presence of various chemicals in hair dye formulations, particularly those containing para-phenylenediamine (PPD) and other similar compounds. These substances can provoke immunological responses in sensitive individuals, leading to symptoms such as itching, redness, and swelling on the scalp or skin where the dye has been applied.

Understanding the significance of allergic reactions in hair coloring is crucial for both barbers and clients. For professionals, it highlights the importance of conducting patch tests prior to applying hair color products, especially for clients who are new to hair dye or have a history of sensitivities. This proactive measure helps prevent potential adverse effects, ensuring a safer experience for the client. Additionally, awareness of allergic reactions can inform barbers about choosing alternative formulations, such as hypoallergenic dyes for those with sensitive skin or prior reactions.