What is a common sign of an allergic reaction to hair dye?

Redness and itching of the skin is a common sign of an allergic reaction to hair dye. This response occurs because many hair dyes contain chemicals like para-phenylenediamine (PPD), which can trigger a hypersensitivity reaction. When an individual is allergic to these substances, the immune system overreacts, leading to inflammation, redness, and itching in areas where the dye has come into contact with the skin.

This reaction can manifest shortly after application or may develop over time with repeated exposure. It's important for clients to conduct a patch test before using new hair dye products to identify any potential allergies and prevent adverse reactions. This awareness helps ensure the safety and comfort of clients during the coloring process.