What can lead to an allergic reaction in hair treatments?

Certain hair dye chemicals can lead to an allergic reaction due to the presence of specific ingredients like para-phenylenediamine (PPD). PPD is commonly found in many permanent hair dyes and is known to cause allergic dermatitis in sensitive individuals. These allergic reactions can manifest as itching, redness, swelling, or even more severe skin conditions.

In contrast, while heat styling tools can cause damage to the hair, they do not involve chemicals that typically elicit allergic responses. Hair extensions and curling products may have their own risks, such as irritation or damage from the physical application, but they do not carry the same potential for chemical allergic reactions as certain hair dye products. Understanding the compositions of these treatments and the potential for allergic responses is crucial for client safety in a cosmetology setting.